Openfermion

Fourth production release. This is a major update introducing many new features:
* Added (alpha version) of a "cloud library" for sharing / storing molecular data files.
* Added routines for generating special FermionOperators such as Sz, S^2, S^+, etc.
* Added SymbolicOperator as parent class from which FermionOperator/QubitOperator inherit.
* Added flexible method of initializing classes derived from SymbolicOperators from strings.
* Fixed some numerical instabilities in sparse operator routines.
* Fixed some minor bugs with the saving and loading of FermionOperator/QubitOperator.
* Added some preliminary routines for generating quantum phase estimation circuits.
* Added substantial infrastructure for generalized fermion transforms based on arXiv:1712.07067.
* Added non-linear encoders for transforming fermions with reduced spatial complexity.
* Changed conventions for how fermion modes are ordered in terms of the spin index.
* Added routines to transform functions for reordering fermion modes prior to transform.
* New demos for Given routine procedures and generalized fermion encodings.

New release makes plugin consistent with breaking changes in OpenFermion core introduced in OpenFermion v0.6.

What's Changed
* Unpins Cirq dependencies. by wjhuggins in https://github.com/quantumlib/OpenFermion-FQE/pull/121
* Enforce req for cirq1.0 by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/122

New Contributors
* wjhuggins made their first contribution in https://github.com/quantumlib/OpenFermion-FQE/pull/121

**Full Changelog**: https://github.com/quantumlib/OpenFermion-FQE/compare/v0.2.0...v0.3.0

Second production release. Minor changes from v0.1 were necessary in order to reflect changes to the way that molecular orbitals are rotated in the core OpenFermion code. OpenFermion-Psi4 is no longer compatible with releases of OpenFermion prior to OpenFermion v0.3.

What's Changed
* Testing workflow by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/1
* Add testing badge by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/2
* Remove factorial scaling setup by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/3
* Removing self._norb from SparseHamiltonian by shiozaki in https://github.com/quantumlib/OpenFermion-FQE/pull/5
* Davidson by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/6
* Molecular data converter by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/7
* Updated readme by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/8
* New example notebook by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/9
* OpenFermion sync, new notebook by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/10
* Low Rank Evolution and Accounting by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/11
* Move Davidson so it usable and correct low-rank by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/12
* Correct Low-rank to be unitary. by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/13
* Custom deepcopy by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/16
* implementing 'inplace' for individual time evolution by shiozaki in https://github.com/quantumlib/OpenFermion-FQE/pull/17
* additional in-place time propagators by shiozaki in https://github.com/quantumlib/OpenFermion-FQE/pull/18
* Vectorized by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/19
* One more pice of code that should be sped up for the Gives example by shiozaki in https://github.com/quantumlib/OpenFermion-FQE/pull/20
* Givens rotation using sparse by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/21
* fix givens by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/22
* get spin-RDMs by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/23
* Diag coulomb improvement by shiozaki in https://github.com/quantumlib/OpenFermion-FQE/pull/25
* Decorator fix by shiozaki in https://github.com/quantumlib/OpenFermion-FQE/pull/28
* Non-spin summed 3-RDM by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/29
* Solving Brillouin conditions by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/30
* final_state is cirq deprecated. by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/32
* Move profiling out of examples by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/33
* Updated docs and intro by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/34
* Improved testing speed by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/35
* Hartree-Fock initialization by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/36
* Linting fqe_ops/ by rmlarose in https://github.com/quantumlib/OpenFermion-FQE/pull/39
* First pass at linting algorithm/ by rmlarose in https://github.com/quantumlib/OpenFermion-FQE/pull/37
* Fix three rdm by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/41
* Fix issue 40 by shiozaki in https://github.com/quantumlib/OpenFermion-FQE/pull/42
* Commutator construction for stationary conditions by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/43
* Clean up Hamiltonians and tests by rmlarose in https://github.com/quantumlib/OpenFermion-FQE/pull/46
* Linting unittest_data by rmlarose in https://github.com/quantumlib/OpenFermion-FQE/pull/49
* Adapt by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/52
* Gradient optimization now available for ADAPT by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/53
* Generalized doubles low-rank factorization by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/56
* Replace unittest with pytest in tensor/ and lint by rmlarose in https://github.com/quantumlib/OpenFermion-FQE/pull/47
* Allow VBC to optimize only over a subset of param by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/57
* Seeks to resolve Issue 58 by shiozaki in https://github.com/quantumlib/OpenFermion-FQE/pull/59
* Update openfermion install by rmlarose in https://github.com/quantumlib/OpenFermion-FQE/pull/61
* Add mypy check to CI and fix mypy errors by rmlarose in https://github.com/quantumlib/OpenFermion-FQE/pull/62
* Speeds up wavefunction.transform by shiozaki in https://github.com/quantumlib/OpenFermion-FQE/pull/64
* Add lint check to CI by rmlarose in https://github.com/quantumlib/OpenFermion-FQE/pull/65
* Low rank general doubles by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/68
* Add format tools and format check to CI by rmlarose in https://github.com/quantumlib/OpenFermion-FQE/pull/67
* Format and polish intro notebook by rmlarose in https://github.com/quantumlib/OpenFermion-FQE/pull/60
* Sos evolution by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/69
* Fix part of issue 70 by shiozaki in https://github.com/quantumlib/OpenFermion-FQE/pull/72
* Updated tutorials by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/74
* Updated documentation by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/75
* Release version by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/76
* Change long description in setup.py for pypi by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/77
* Cirq version update by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/78
* Call format instead of directly calling yapf by rmlarose in https://github.com/quantumlib/OpenFermion-FQE/pull/79
* minor cleanup by shiozaki in https://github.com/quantumlib/OpenFermion-FQE/pull/80
* Prepare to add FQE docs to devsite by rmlarose in https://github.com/quantumlib/OpenFermion-FQE/pull/81
* Call normalize in set_wfn when strategy is random by rmlarose in https://github.com/quantumlib/OpenFermion-FQE/pull/83
* Improved preset for exit by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/84
* User sets max-expansion without intervention by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/85
* Aim to resolve 86 by shiozaki in https://github.com/quantumlib/OpenFermion-FQE/pull/87
* Updated citation by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/88
* Remove docs/ and update README by rmlarose in https://github.com/quantumlib/OpenFermion-FQE/pull/89
* Remove loops in exchange for einsum variables by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/94
* Use string format for algorithm iteration printouts by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/96
* Add script to build api reference docs by rmlarose in https://github.com/quantumlib/OpenFermion-FQE/pull/93
* user can limit number of terms optimized in adapt by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/97
* Docstrings update related to 99 by shiozaki in https://github.com/quantumlib/OpenFermion-FQE/pull/100
* Update requirements by rmlarose in https://github.com/quantumlib/OpenFermion-FQE/pull/91
* Add C-accelerated code by awhite862 in https://github.com/quantumlib/OpenFermion-FQE/pull/103
* Make sure C code can be fully disabled, small improvement for quadratic Hamiltonian evolution by awhite862 in https://github.com/quantumlib/OpenFermion-FQE/pull/104
* add Cython to requirements by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/106
* Using manifest.in to include missing files by klgunst in https://github.com/quantumlib/OpenFermion-FQE/pull/107
* Fix tutorial by awhite862 in https://github.com/quantumlib/OpenFermion-FQE/pull/110
* Update docs by awhite862 in https://github.com/quantumlib/OpenFermion-FQE/pull/112
* cirq_of_version_bump by ncrubin in https://github.com/quantumlib/OpenFermion-FQE/pull/114

New Contributors
* ncrubin made their first contribution in https://github.com/quantumlib/OpenFermion-FQE/pull/1
* shiozaki made their first contribution in https://github.com/quantumlib/OpenFermion-FQE/pull/5
* rmlarose made their first contribution in https://github.com/quantumlib/OpenFermion-FQE/pull/39
* awhite862 made their first contribution in https://github.com/quantumlib/OpenFermion-FQE/pull/103
* klgunst made their first contribution in https://github.com/quantumlib/OpenFermion-FQE/pull/107

**Full Changelog**: https://github.com/quantumlib/OpenFermion-FQE/commits/v0.2.0

First production release! Improvements over previous alpha version includes:
* Added overlap integrals back into being stored from Psi4.
* Updated README with citations.