Removed references to old repo in README

Changed 3 links from gunark/rubycas-client.git to rubycas/rubycas-client.git.
Merge pull request #70 from billgathen/patch-1

Removed references to old repo in README
Explicitly test for ActionController::Base in addition to Rails

The code uses ActionController::Base, but it is possible to have Rails
defined, but not ActionController::Base. In the old situation, the code
would have raised due to ActionController::Base not being defined.
Remove rails method 'blank?'
add before method
fixed the bug
Merge pull request #74 from cassiuschen/feature/UpdateToRails4.1

Update to Rails 4.1
Merge pull request #71 from Narnach/no-rails

Explicitly test for ActionController::Base in addition to Rails
Merge pull request #72 from KrauseFx/master

Remove rails method 'blank?'
update travis config to get rbx working again
merge changes on master into rails4-fix branch