Develop a GRASS Conda package that will be useable across multiple OS platforms

[cmbarton]

A common request of the GRASS user community and one of the planned activities of the NSF POSE grant is to make it possible to install GRASS as a package in the widely used Anaconda environment for Python. Some initial discussions, as well as test code have been started here.

I'm opening this issue on the GRASS repository to broaden the discussion of this effort to the entire GRASS community and encourage those familiar with GRASS, Python, and Conda to contribute to the effort.