Weary relax dependencies

- Relax multi_json and webmock dependencies
- Fix typhoueus to work with typhoeus > 0.5 and enfore newer versions
- Remove Gemfile.lock. See [this article](http://yehudakatz.com/2010/12/16/clarifying-the-roles-of-the-gemspec-and-gemfile/) for why gemfile.lock should not be checked in no gems