Fix broken pipe error when checking pip packages.
Fix broken pipe error when checking pip packages.

The -q flag causes grep to close stdin as soon as it finds a match.
This upsets pip, which results in the following error, although the
command still works as expected overall.

```
Checking required PIP packages: Traceback (most recent call last):
  File "/usr/bin/pip", line 9, in <module>
    load_entry_point('pip==1.5.4', 'console_scripts', 'pip')()
  File "/usr/lib/python2.7/dist-packages/pip/__init__.py", line 235, in
main
    return command.main(cmd_args)
  File "/usr/lib/python2.7/dist-packages/pip/basecommand.py", line 156,
in main
    logger.fatal('Exception:\n%s' % format_exc())
  File "/usr/lib/python2.7/dist-packages/pip/log.py", line 111, in fatal
    self.log(self.FATAL, msg, *args, **kw)
  File "/usr/lib/python2.7/dist-packages/pip/log.py", line 164, in log
    consumer.flush()
IOError: [Errno 32] Broken pipe
OK
```

ixdy/kubernetes-release,kubernetes/release,kubernetes/release,ixdy/kubernetes-release