Summary of Changes:

BatchRunnerMP
----
- removed pathos (unneccessary as unordermap in pathos is same as multiprocessing)
- refactored so compatible with Windows, Mac and Linux OS

Batchrunner
----
- add two functions
	- get_collector_model: returns dictionary of dataframes for datacollector model reporters
	- get collector_agents: returns dictionary of dataframes for datacollector agent reporters
	(key for dictionaries is unique parameter variation with iteration number)

DataCollector
----
- expanded to allow more collection types to be passed in model reporter (agents are handled internally). This was necessary to becuase lambda cannot be used at the mudel level for multiprocessing
key_name: <class attribute>
key_name: function (e.g schedule.get_agent_count)
key_name: lambda function
key_name: [function, [<arguments for function>]