I have installed omniauth 1.0. Also I have oauth-0.4.5, oauth2-0.5.1, omniauth-facebook-1.0.0, omniauth-twitter-0.0.6.
omniauth.rb
Rails.application.config.m
There have been breaking changes made in omniauth 1.0 - https://github.com/intridea/omniauth
OmniAuth 1.0 has several breaking changes from version 0.x. You can set the dependency to ~> 0.3.2 if you do not wish to make the more difficult upgrade. See the wiki for more information.
I would try reverting omniauth to 0.3.2:
gem install omniauth --version '~> 0.3.2'
or if you're using bundler, in your Gemfile:
gem omniauth, '~> 0.3.2'