Remove overide of reset!

Capybara update
https://github.com/jnicklas/capybara/commit/de13ec1d85ba1152b6566e1d1e71271d29dd7a28
in 2.2.1 resolves this work around
https://github.com/saucelabs/sauce_ruby/commit/096f61efb666fd870009f5b855a3d3f88b02ef58
Add capybara as dependency to gemspec
Merge pull request #190 from mrloop/master

Remove reset! override