fix quoting inconsistency; simplify parse_iso8601tz() implementation
fix quoting inconsistency; simplify parse_iso8601tz() implementation

googlearchive/compute-appengine-timeout-python,mahmoud76/compute-appengine-timeout-python,googlearchive/compute-appengine-timeout-python,jonparrott/compute-appengine-timeout-python,mahmoud76/compute-appengine-timeout-python,jonparrott/compute-appengine-timeout-python