Add db configuration to modifying config

Move more tests over

config_app/config_endpoints/api/suconfig.py

@@ -76,6 +76,11 @@ class SuperUserConfig(ApiResource):
     # Write the configuration changes to the config override file.
     config_provider.save_config(config_object)
 
+    # now try to connect to the db provided in their config to validate it works
+    combined = dict(**app.config)
+    combined.update(config_provider.get_config())
+    configure(combined, testing=app.config['TESTING'])
+
     return {
       'exists': True,
       'config': config_object