Revert "Retry request 5x when the response is in the 4xx range before raising an exception."

This reverts commit b3049c3b88ba48123e531c2ef627d2c21ac051e4.

Conflicts:
	README.rst
Recover from exceptions in the greenlets.
Merge pull request #32 from brocaar/recover_worker_event_loop

Recover from exceptions in the greenlets