Arbitrage: Resume - backwards compatibility, dry run resume, Configuration Object (3.5 days)

[jaonewguy]

In relation to #177, we need to persist the DryRunExchanges to properly "resume" the bot run with the internal balances.

Edit:

• Make self.config a namedtuple or Class, incorporate #192 into this change.
• Create a new main module to re-insert an old version of FCFCheckpoint with a new version.