Activate the environment variables set by the installer on tests.
Activate the environment variables set by the installer on tests.

This way we can verify that the installer sets them as expected.

larskanis/rubyinstaller2,larskanis/rubyinstaller2,oneclick/rubyinstaller2,oneclick/rubyinstaller2,oneclick/rubyinstaller2,larskanis/rubyinstaller2