add logout functionality to passport
Merge pull request #28 from zamiang/new-logout

@craigspaeth Add logout functionality to artsy-passport
add myself as a contributor
Merge pull request #29 from zamiang/contributor

@craigspaeth Add myself as a contributor
correctly get and delete access token
Merge pull request #30 from zamiang/token

@zamiang Correctly get and delete access token
add test for logout if calling logout deletes req.user
check if req.user is destroyed on all passport logout tests
Merge pull request #31 from zamiang/logout-test

@dblock Add test for logout if calling logout deletes req.user