Make the retry strategy configurable

* The previous behaviour is kept by having the default retry amount
to be one, and the retry wait to be zero.
* The configurable retry strategy allows for a backing off of retry
attempts when network conditions prevent a simple strategy from
working.
* Based on @AeroNotix patch here -->
https://github.com/dieswaytoofast/erlasticsearch/commit/8f818ce97af51504f5a9f4e64dd37c6bf971d11d