Brakes Versions Save

• Fixes issue described in https://github.com/awolden/brakes/issues/120 where stats stream stops reporting

• Will now gracefully handle an undefined error.

slaveCircuits have been renamed to subCircuits to help erase prejudicial language.

• Added a toggle to disabled prefixing error message with circuit name

• Added cumulative counters that are independent of buckets. These counter stream out total requests (timeouts, etc.) per breaker, as well as the diff between two report events.

• Adds in the concept of circuit generations. A generation will be an integer that increments by one every time a circuit is opened. Service requests will be tagged with a generation and the generation will be checked on failed response to make sure we don't inadvertently pollute the current circuit with requests that are from a previous circuit generation.
• Add the breaker name to circuit rejections

• Updates regex detection for callback detection when passing a function

• Fixes issue found in #78. Slave circuits weren't using master fallback when circuit was open.

• The timeout and failure event now provides the underlying error as the second argument.

• Added isPromise and isFunction options to Brakes. These options will force the library to treat functions that are passed in as either promises or callbacks.
• Fixed an issue where errorPercentage in the hystrixStream was not being aggregated by turbine correctly due to being a float