Travic CI tweaks
Travic CI tweaks

- add Ruby 2.2
- exclude Rails 3.2 on Ruby 2.2
- disable use of sudo

zorab47/activeadmin-sortable-tree,hotvulcan/activeadmin-sortable-tree,zorab47/active_admin-sortable_tree,hotvulcan/activeadmin-sortable-tree,zorab47/active_admin-sortable_tree,zorab47/active_admin-sortable_tree,zorab47/activeadmin-sortable-tree,zorab47/activeadmin-sortable-tree,hotvulcan/activeadmin-sortable-tree