Feature: Retry with exponential backoff

[samuelgiles]

At the moment we're wrapping around the outside of the Voucherify SDK to rescue + inspect the errors it raises to implement our own retry mechanism to deal with the odd timeout and very occasionally an odd network error or two.

Are there any plans to build a retry mechanism into the Ruby SDK à la Stripe's Ruby client?

See here for Stripe's implementation: https://github.com/stripe/stripe-ruby/blob/master/lib/stripe/stripe_client.rb#L451

If we were to put aside the time to move our retry mechanism into this gem would @voucherifyio be open to merging this in rather than us maintaining our own fork?