Merge pull request #2 from developerauction/master

Fixes LinkedIn endpoints. Renames provider name to simply :linkedin
Added licence to gemspec. Closes #3
Update example/config.ru to use the renamed provider name
Merge pull request #9 from jrichardlai/master

Update example/config.ru to use the renamed provider name
Fixes issue with query params vs. post body: http://developer.linkedin.com/forum/unauthorized-invalid-or-expired-token-immediately-after-receiving-oauth2-token