Pyrcel

This minor release improves some basic packaging elements and streamlines several bugfixes introduces by changes in upstream libraries.

This is minor version release reflected the re-factoring and re-naming of the project from 'parcel_model' to 'pyrcel'. The model is scientifically identical to v1.2.0.

This release denotes an overhaul of the model documentation and modernization of its codebase, instigated on the release of [Rothenberg and Wang (2016)](http://journals.ametsoc.org/doi/abs/10.1175/JAS-D-15-0223.1). The scientific description of the model in that article is still accurate and is reflected in this release of the code, but the model has been processed to update documentation where out-of-date and to enable compatibility between Python 2 and Python 3.

This milestone denotes the final development of the original moving-grid parcel model intended for aerosol activation studies. It has a module of activation parameterizations which can be compared against the parcel model, and has all the features necessary to do idealized activation experiments. Furthermore, it is nearly identical to the version used to generate the activation scheme of Rothenberg and Wang (2015, _in prep_) (the only changes relate to IO facilities and some superficial changes to make the model simpler to run).

Further refinements and bugfixes to this scheme will issued on the branch [moving_grid](https://github.com/darothen/parcel_model/tree/moving_grid). However, future development on the parcel will deviate sharply form this formulation in order to introduce more sophisticated microphysics.

Some minor improvements, including adding basic IO.