Issues/raygun 3 add bootstrap compatible paging kaminari

Hi Christian

Here is the pull request for adding Kaminari to the raygun-rails4 template. It was fairly straightforward, I stuck with defaults for paging size and so forth. I did include the actual views for customizing the paging links.  
I believe it is complete - I modified the index view template, the controller scaffold template and the rspec templates.

I did find a small bug in the _form scaffold which I fixed. (Just a spacing issue).

I generated an example of this at https://github.com/drogar/raygun_with_kaminari_test 
If you want to try that, you just have to clone it, do a rake db:setup and rake db:sample_data. The root page has a button link to a list that goes over 5 pages.

Given the new functionality of raygun - once you finish 112 - I suppose you may not want to merge this into master. I think it could work well as a branch or a second repository.