Add licenses to gemspec

This should be enough to have it show up on rubygems.org
Merge pull request #376 from coreyhaines/patch-1

Add licenses to gemspec
Support API versions in all requests
Support API versions in OAuth URLs
Update changelog
Merge pull request #377 from arsduo/additional-versioning

Support API versions in other places
Bump version
Merge branch 'master' of github.com:arsduo/koala