Add a --start-at-departure option for dispatch_go_to_place (#331)

* Add a --start-at-departure option for dispatch_go_to_place

Signed-off-by: Michael X. Grey <greyxmike@gmail.com>

* fix style

Signed-off-by: Michael X. Grey <greyxmike@gmail.com>

---------

Signed-off-by: Michael X. Grey <greyxmike@gmail.com>

Author: mxgrey

rmf_demos_tasks/rmf_demos_tasks/dispatch_go_to_place.py

@@ -105,6 +105,15 @@ def __init__(self, argv=sys.argv):
                 'setting.'
             ),
         )
+        parser.add_argument(
+            '--start-at-departure',
+            action='store_true',
+            help=(
+                'Request the robot to not start going to its destination '
+                'until the task start time has been reached, rather than '
+                'trying to arrive at the destination at the task start time.'
+            )
+        )
 
         self.args = parser.parse_args(argv[1:])
         self.response = asyncio.Future()
@@ -171,6 +180,9 @@ def __init__(self, argv=sys.argv):
                 {'category': 'prefer_same_map'}
             ]
 
+        if self.args.start_at_departure:
+            go_to_description['start_at_departure'] = True
+
         go_to_activity = {
             'category': 'go_to_place',
             'description': go_to_description,