including MRI Ruby 2.1.0 in .travis.yml
updating license information (https://github.com/kbeckman/omniauth-wsfed/issues/11)
bumping omniauth version to 1.2.0+ (https://github.com/kbeckman/omniauth-wsfed/issues/13)
Travis CI config changes (aligning with omniauth 1.2.2)