Implement wait for node primary/secondary in CLI

Use a different wait method of querying the node status every
half-second during the transition, in order to wait on the transition to
complete if desired.

Closes #72

client-cli/cli_lib/common.py

@@ -78,8 +78,7 @@ def call_api(config, operation, request_uri, params=None, data=None, files=None)
                 data=data
             )
     except Exception as e:
-        click.echo('Failed to connect to the API: {}'.format(e))
-        exit(1)
+        return False, 'Failed to connect to the API: {}'.format(e)
 
     # Display debug output
     if config['debug']: