Updating Gemfile to use the https rubygems source

plus the resulting Gemfile.lock, which appears to not have been updated
since the version bump to `0.0.3`.
Backing out the Gemfile.lock changes per feedback
Merge remote-tracking branch 'upstream/master' into gemfile-updates
Dropping the Gemfile.lock per @joshk feedback
Adding some pessimistic version locks to gemspec

also per feedback from @joshk, although he didn't mention exactly what
kind of version locks and on which dependencies...
Merge pull request #7 from meatballhat/gemfile-updates

Updating Gemfile to use the https rubygems source