Multiflow

- Readme
- Minor non-breaking name change of internal variable

- Better support for getting arguments and kwargs from the `JobOutput` class as well as passing args and kwargs between flow functions
- More options for getting the successful and failed job counts
- Adds ability to fail fast a job by wrapping the exception with `FlowFailFastException`
- Adds map function
- Fixes no logger error if passing `log_all` or `log_summary` but not logger
- Makes some error messages more clear

* Adds ability to get an argument value from `JobOutput` using the `get()` function - or in other words, like a kwarg

* Adds the ability to get the args and kwargs within each `JobOutput` instance
* Adds a parameter called `log_all` which is a shortcut for enabling periodic, retries, errors, and summary log messages

Initial release of Multiflow!