A star module

@bballtwenty8 @noahdela 

I have implemented or rather taken an existing a star implementation from:
www.redblobgames.com/pathfinding/a-star/implementation.html

Also, I have put some stuff in component.py in util where I use the enviroment_state to store the state of all the components in the system. Whereas the truck and dumpster objects act as an intermediate data structure helping in parsing to the a star search.

I am yet to work on the heuristics which I have not started, though it runs some existing heuristics.

Also, I had to change iDumpster to include "type", updated location as a dict rather than a string, Added json encoder for enum data type.

I know it is a very bad coding. But, I am totally open for any levels of criticisms :)

Thanks,
This shouldn't change the functionality since Python always returns None if theres no return statement, but I don't think this should be indented as far.  If isinstance fails then get_credentials will never reach a return statement.