Added support for buttons from Cloud Tenant summary screen.

- Added support for buttons when going to list of Instance/Images thru relationships from Cloud Tenant summary screen.
- Added spec tests for routes under cloud tenants and spec test to verify that button method is added to cloud tenant controller.
- Fixed a typo in edit_form_buttons view for reset button.

https://bugzilla.redhat.com/show_bug.cgi?id=1138838
https://bugzilla.redhat.com/show_bug.cgi?id=1138188
Merge pull request #545 from h-kataria/fix_cloud_tenants_relationship_buttons

Added support for buttons from Cloud Tenant summary screen.