nagios: Move cron_file_helper from bots/ to scripts/lib.

This ensures the tool is available in Zulip production deployments.

bots/cron_file_helper.py

@@ -1,34 +0,0 @@
-#!/usr/bin/env python2.7
-import time
-
-def nagios_from_file(results_file):
-    """Returns a nagios-appropriate string and return code obtained by
-    parsing the desired file on disk. The file on disk should be of format
-
-    %s|%s % (timestamp, nagios_string)
-
-    This file is created by various nagios checking cron jobs such as
-    check-rabbitmq-queues and check-rabbitmq-consumers"""
-
-    data = open(results_file).read().strip()
-    pieces = data.split('|')
-
-    if not len(pieces) == 4:
-        state = 'UNKNOWN'
-        ret = 3
-        data = "Results file malformed"
-    else:
-        timestamp = int(pieces[0])
-
-        time_diff = time.time() - timestamp
-        if time_diff > 60 * 2:
-            ret = 3
-            state = 'UNKNOWN'
-            data = "Results file is stale"
-        else:
-            ret = int(pieces[1])
-            state = pieces[2]
-            data = pieces[3]
-
-    return (ret, "%s: %s" % (state, data))
-