feeder level agent_area_dict given by switch and secondary area level context managers

[afisher1]

Describe the bug
I created some instances of switch and secondary area agents with no context dictionaries so that they would have to query the example context managers for their context dictionaries. These agents received the context for the feeder level and not the context for their area specifically. If this is by design know that I have addressed errors due to this behavior in GRIDAPPSD/gridappsd-python#121 and thus this issue can be closed with no additional actions needed.

Steps to reproduce
run the example context manager script and in a separate file instantiate an instance of SwitchAreaAgent and/or SecondaryAreaAgent with the switch_area_dict and/or secondary_area_dict arguments none. When calling connect for those agents you will see that the self.agent_area_dict variable contains the feeder level context and not the local switch area or secondary area context.

[AAndersn]

@afisher1 - This might be the wrong repo - this is the centralized sample app, which does not have any distributed agents