Updates to server

[balloch]

we should review whether CurrentState and InitState ought to be in common, and we need to ensure that alfworld_server is programmatically in the PYTHONPATH so it can reach common. Lastly, it should be detailed in the README how to switch the local data paths

[balloch]

• common.AtomicAction should be subclasses of common.Task, or just done away with all-together and be instantiated as Task where self.primitive_fn is not None
• The "pickupobject" atomicaction should have the "add_effect" of ('objectAtLocation','?o','?a')
• The "putobject" atomicaction should have the "del_effect" of ('objectAtLocation','?o','?a')
• The variables in the command_template of an atomic action needs to match the appropriate parameter name from the preconditions.