Updates gem dependencies

Needed to get tests to execute under recent Ruby 1.9.3 versions.
Removes .rvmrc file
Merge branch 'pagination' of https://github.com/jdsn/github-v3-api into jdsn-pagination

* 'pagination' of https://github.com/jdsn/github-v3-api:
  support github api pagination
spec: have strings behave like strings that return from RestClient