Change shebangs from python2.7 to python.

bots/check-mirroring

@@ -1,4 +1,4 @@
-#!/usr/bin/env python2.7
+#!/usr/bin/env python
 from __future__ import print_function
 from __future__ import absolute_import
 import sys

bots/gcal-bot

@@ -1,4 +1,4 @@
-#!/usr/bin/env python2.7
+#!/usr/bin/env python
 from __future__ import print_function
 import sys
 import time

bots/irc-mirror.py

@@ -1,4 +1,4 @@
-#! /usr/bin/env python2.7
+#!/usr/bin/env python
 #
 # EXPERIMENTAL
 # IRC <=> Zulip mirroring bot

bots/jabber_mirror.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python2.7
+#!/usr/bin/env python
 # Copyright (C) 2014 Zulip, Inc.
 #
 # Permission is hereby granted, free of charge, to any person

bots/jabber_mirror_backend.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python2.7
+#!/usr/bin/env python
 #
 # Copyright (C) 2013 Permabit, Inc.
 # Copyright (C) 2013--2014 Zulip, Inc.

bots/log2zulip

@@ -1,4 +1,4 @@
-#!/usr/bin/env python2.7
+#!/usr/bin/env python
 from __future__ import print_function
 import subprocess
 import os

bots/process_ccache

@@ -1,4 +1,4 @@
-#!/usr/bin/env python2.7
+#!/usr/bin/env python
 import sys
 import subprocess
 import base64

bots/sync-public-streams

@@ -1,4 +1,4 @@
-#!/usr/bin/env python2.7
+#!/usr/bin/env python
 import sys
 import os
 import logging

bots/tddium-notify-humbug

@@ -1,4 +1,4 @@
-#!/usr/bin/env python2.7
+#!/usr/bin/env python
 # Copyright (C) 2012 Zulip, Inc.
 #
 # Permission is hereby granted, free of charge, to any person

bots/zephyr_mirror.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python2.7
+#!/usr/bin/env python
 # Copyright (C) 2012 Zulip, Inc.
 #
 # Permission is hereby granted, free of charge, to any person

bots/zephyr_mirror_backend.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python2.7
+#!/usr/bin/env python
 # Copyright (C) 2012 Zulip, Inc.
 #
 # Permission is hereby granted, free of charge, to any person