Add tabs for database
Redirect to mx_tables#index when access mx_databases#show
Change helper method name to mx_cell_class_for from class_for
Add tests for mx tab and mx_databases#index
Add tests for mx_databases#show
Add tests for mx_databases#new, edit, destroy
Change existed to taken
Add tests for mx_datbases#create, update
Use assert_conflict_flash
To DRY on testcase with deleted param