Add support for generic OAuth2 access token in v3 API client
Updates Oauth2 versions to accommodate version 0.9.x
Merge branch 'v3_api_generic_oauth2_access_token' of github.com:fzagarzazu/bitly into fzagarzazu-v3_api_generic_oauth2_access_token
Bumps version to 0.10.0.
Updates version to 0.10.0
Adds latest rakefile/gemspec