Remove back capability for PyGChem 0.2.0
Remove back capability for PyGChem 0.2.0

No one in the atmospheric modelling group at York has been using 0.2.0 for years and the back capability is now causing issues with Py3 / basemap etc. so it has been removed. The legacy python 2.7 code (master.legacy_py2_7) will retain back capability.

tsherwen/AC_tools,tsherwen/AC_tools