v2.0.0

• Require ruby 2.0+.
• Time intervals default to randomized exponential backoff instead of fixed time intervals. The delay between retries grows with every attempt and there's a randomization factor added to each attempt.
• base_interval, max_interval, rand_factor, and multiplier are new arguments that are used to generate randomized exponential back off time intervals.
• interval argument removed.
• Accept intervals array argument to provide your own custom intervals.
• Allow configurable defaults via Retriable#configure block.
• Add ability for :on argument to accept a Hash where the keys are exception types and the values are a single or array of Regexp pattern(s) to match against exception messages for retrial.
• Raise, not return, on max elapsed time.
• Check for elapsed time after next interval is calculated and it goes over the max elapsed time.
• Support early termination via max_elapsed_time argument.