Add a version check to load script

[xylar]

If the load script is for a different compass version, a developer is told to rerun the configure script.

Checklist

• Developer's Guide has been updated
• Documentation has been built locally and changes look as expected
• Document (in a comment titled Testing in this PR) any testing that was used to verify the changes

[xylar]

Testing

If the version in compass/version.py matches the version in the load script, the everything proceeds as usual when the load script gets sourced. If the versions don't match, the output is something like:

$ source load_compass_test_morpheus_gnu_openmpi.sh 
This load script is for a different version of compass:
__version__ = '1.2.0-alpha.6'

Your code is version:
__version__ = '1.2.0-alpha.7'

You need to run ./conda/configure_compass_env.py to update your conda 
environment and load script.