curl out for ros params

[minshallj]

starting with the attract loop's timeout (/lg_activity/activity_timeout) ros param, create a way to curl out to a parameterized url in order to obtain ros params. If it doesn't exist on the server, you'll get a non-200 HTTP response, so go back to the old behavior of taking the param out of rospy.get_param.

Create this function in https://github.com/EndPointCorp/lg_ros_nodes/blob/d0c9bfd3771188e6c43b9740d0b1bf5e2625c7d4/lg_common/src/lg_common/helpers.py we could potentially replace all rospy.get_param calls with this, but for now only replace those we want to curl