Elasticipy

Fix wrong path to requirements.txt, which prevents Conda build

Remove duplicate build section, which avoids Conda build

Fix error in filename for Conda build

Fix error for Conda built

This release is mainly meant to integrate Conda as a package manager

This release mainly introduces compatibilities with other packages dedicated to crystallographic analyses, namely:
- [pymatgen](https://pymatgen.org/),
- [orix](https://orix.readthedocs.io/).

Evaluation of statistics for ``SphericalFunction`` and ``HyperSphericalFunction`` (e.g. ``.mean()`` or ``.std()``) now take advantage of broadcasting, therefore speeding them up (~10 times faster).

The input matrix for creating a ``StiffnessTensor`` or a ``ComplianceTensor`` now must be symmetric and definite positive (except if ``check_symmetry=True`` and ``check_positive_definite=False``, respectively).

**Full Changelog**: https://github.com/DorianDepriester/Elasticipy/compare/v2.6.0...v2.7.0