WIP: all tests pass

Documentation needs some improvement

The API has been simplified to only allow for ONE topology per
NetworkEnvironment.
This covers the main use case, and simplifies the code.

examples/custom_timeouts/custom_timeouts.py

@@ -15,6 +15,7 @@ class Fibonacci(FSM):
         prev, self['prev'] = self['prev'], max([self.now, self['prev']])
         return None, self.env.timeout(prev)
 
+
 class Odds(FSM):
     '''Agent that only executes in odd t_steps'''
     @default_state
@@ -23,9 +24,8 @@ class Odds(FSM):
         self.log('Stopping at {}'.format(self.now))
         return None, self.env.timeout(1+self.now%2)
 
+
 if __name__ == '__main__':
-    import logging
-    logging.basicConfig(level=logging.INFO)
     from soil import Simulation
     s = Simulation(network_agents=[{'ids': [0], 'agent_class': Fibonacci},
                                    {'ids': [1], 'agent_class': Odds}],