-----------------
* [oneshot] refactoring using before_step in greedy
* [minor] formating update
* [bugfix] production costs were not increasing. closes 38
* [API] Adding before_step() to all agents. If a method called `before_step()` is defined for an agent, it will be called once every simulated day before any other calls to the agent but after all exogenous contracts and ufun parameters are fixed. Note that `step()` is called at the *end* not the beginning of the day.
* [oneshot] limiting exogenous quantities to n lines. This closes 37
* [oneshot] Aspiration negotiator gets more agreements
* [oneshot] allowing agents to skip their turn. Agents can skip their turn now by returning REJECT_OFFER, None
* [oneshot] GreedyOneShotAgent is more rational now
* [bugfix] avoiding an inconsistency in path names for logs
* [oneshot] improved builtin agents (aspiration)
* [tournament] avoiding a possible edge case that would have led to competitor agents appearing as non-competitors
* [tournament] Saving negotiatinos by default in the CLI and utils
* [std/coll] defaulting to narrower worlds