Need a try/Except loop around _make_request call in _mexe

[meyerkev]

File "appoptics_metrics/init.py", line 481, in create_alert
resp = self._mexe("alerts", method="POST", query_props=payload)
File "appoptics_metrics/init.py", line 189, in _mexe
resp = self._make_request(conn, path, headers, query_props, method)
File "appoptics_metrics/init.py", line 151, in _make_request
return conn.getresponse()
File "/usr/lib/python2.7/httplib.py", line 1123, in getresponse
raise ResponseNotReady()
ResponseNotReady

I'll write a patch tomorrow, that moves that _make_request call down one line, when I'm not sitting down to dinner.