Run rake test without bundler
Run rake test without bundler

bundler modifies the PATH which interferes with our expectations
to enable_msys_apps and disable_msys_apps.

In particular: Bundler removes dups in the PATH, with the result, that
disable_msys_apps removes Ruby's bin entirely from the PATH.

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