Added views_bulk_operations module and views_access_callback. Modified the views attendee certificate to allow the new callback created. Created a new view called User VBO that modifies the role assigned to each user. Ticket #148.
Merge pull request #149 from Luukyb/views-vbo-148

Added views_bulk_operations module and views_access_callback.......
recreated views user role assign VBO. Ticket #148.
Updated the path for views user-role-assign-vbo. Tickt #148.
Merge pull request #150 from Luukyb/views-vbo-148

Views vbo 148
Merge branch 'develop'