only initialize config in setUp, not on import of test module; run options unit tests first
make config.get_modules_tool() and modules.modules_tool() robust against uninitialized config (fixes #674)
add clarifying comment
Merge branch 'develop' into fix_list-toolchains
fix docstring
Merge pull request #675 from boegel/fix_list-toolchains

fix 'eb --list-toolchains'