Windows support

[pllim]

There was a request for Windows support.

ref: INC0157637

Also see spacetelescope/calcos#169

[Rplesha]

A user commented in #10 how they were able to get costools installed on a windows machine, leading me to believe that this has to do with the packaging in astroconda, not specific to code, no?

[pllim]

conda-forge is also an option if conda distribution is desired and astroconda cannot provide.

[stscirij]

calcos needs a c compiler, so if we want to support windows, we will need to test on windows. Setting up that infrastructure on windows is probably a significant amount of work. Alternatively, we can instruct the users to make sure they have a C compiler and then do python setup.py install but not offer further support