Relax angular dependency so that 1.3.0-beta can be installed

I am using `ng-table` through http://rails-assets.org (I have `rails-assets-ng-table` entry in my `Gemfile`). I found it impossible to upgrade Angular to `1.3.0.beta10` because of `ng-table` dependency on Angular 1.2. I've done some tests and looks like `ng-table` is working good with Angular 1.3.0.