Update gemfile

Had I updated to latest develop first, I probably wouldn't have this PR.

It does loosen some of the version constraints a bit more.  I'm in favor of removing constraints when we can, and only re-introducing when a problem develops when we update.

Mostly removes the constraint on capybara and fixes the one selector problem that this creates (an ambiguity on a click step).

Use it or skip it at your discretion.