Bugfixes for ResilientSession retry logic
Bugfixes for ResilientSession retry logic

* max_reties should mean retries, not attempts
* If all attempts fail, re-raise the last exception (instead of
    returning None!?)
* Don't call raise_on_error()  with an Exception, it needs a response!

pycontribs/jira,dwmarshall/pycontribs-jira,stevencarey/jira,milo-minderbinder/jira,dwmarshall/pycontribs-jira,milo-minderbinder/jira,stevencarey/jira,pycontribs/jira