Don't re-require gems in travis
Remove unsupported databases from test stuff

And get rid of the duplicate mysql loading for travis.
Remove cucumber from the gemfile

Which means we have to explicitly declare capybara as a dependency,
since we were getting that through cucumber's dependencies before.
Update capybara

Because rspec complains about deprecated matcher syntax. This update
fixes it.
Removes test-unit gem

I don't even know.
Remove explicit nokogiri dependency

Nothing seems to change by removing this
Merging #36