Finalize the Windows build

[moorepants]

Simbody currently builds just fine on appveyor, but there is some kind of windows-conda activate bug that occurs when the test environment is activated. This needs to be addressed so that Simbody is available on all platforms through conda.

[moorepants]

Here is an example of the fail: https://ci.appveyor.com/project/conda-forge/staged-recipes/build/1.0.4775/job/rgxdm99t8n9hru2s

TEST START: simbody-3.5.3-vc14_200
Fetching package metadata .............
Solving package specifications: ..........
The following packages will be downloaded:
    package                    |            build
    ---------------------------|-----------------
    simbody-3.5.3              |         vc14_200        12.6 MB  local
The following NEW packages will be INSTALLED:
    python:  3.5.2-1        conda-forge
    simbody: 3.5.3-vc14_200 local       [vc14]
(root) C:\Miniconda35\conda-bld\test-tmp_dir>call activate.bat C:\Miniconda35\envs\_test 
TESTS FAILED: simbody-3.5.3-vc14_200
Command exited with code 1

[moorepants]

Here is a reference to the issue where @msarahan has been asked to look into the failure:

conda-forge/staged-recipes#161 (comment)