Merge pull request #1 from rakyll/master

Adding OAuth 2.0 middleware to allow logins via OAuth 2.0 providers
Merge pull request #3 from rakyll/master

Provide oauth2.LoginRequired handler
Works with Facebook as well.
Merge branch 'master' of github.com:martini-contrib/oauth2
Fix example in the README
Add wrecker.yml
Add wercker badge
Merge pull request #6 from superlogical/master

Fix example in the README
Fix README
Merge pull request #8 from superlogical/master

Fix README
Injected tokens are never null, instead use tokens.IsExpired().
LoginRedirect redirects to the current page after logging user in.
Simplify the usage manual.