ignore unicode errors in stdout

When running 'pacman -Syu' on a fresh Arch deployment via the 'raw' module, I get the following traceback:

    TASK: [Upgrade packages] ******************************************************
    fatal: [grego] => Traceback (most recent call last):
      File "/usr/local/brew/lib/python2.7/site-packages/ansible/runner/__init__.py", line 344, in _executor
        exec_rc = self._executor_internal(host)
      File "/usr/local/brew/lib/python2.7/site-packages/ansible/runner/__init__.py", line 416, in _executor_internal
        return self._executor_internal_inner(host, self.module_name, self.module_args, inject, port, complex_args=complex_args)
      File "/usr/local/brew/lib/python2.7/site-packages/ansible/runner/__init__.py", line 592, in _executor_internal_inner
        self.callbacks.on_ok(host, data)
      File "/usr/local/brew/lib/python2.7/site-packages/ansible/callbacks.py", line 449, in on_ok
        msg = "%s: [%s] => %s" % (ok_or_changed, host, utils.jsonify(host_result2))
      File "/usr/local/brew/lib/python2.7/site-packages/ansible/utils/__init__.py", line 133, in jsonify
        return json.dumps(result2, sort_keys=True)
      File "/usr/local/brew/Cellar/python/2.7.5/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/__init__.py", line 250, in dumps
        sort_keys=sort_keys, **kw).encode(obj)
      File "/usr/local/brew/Cellar/python/2.7.5/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/encoder.py", line 209, in encode
        chunks = list(chunks)
      File "/usr/local/brew/Cellar/python/2.7.5/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/encoder.py", line 434, in _iterencode
        for chunk in _iterencode_dict(o, _current_indent_level):
      File "/usr/local/brew/Cellar/python/2.7.5/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/encoder.py", line 390, in _iterencode_dict
        yield _encoder(value)
    UnicodeDecodeError: 'utf8' codec can't decode byte 0xe4 in position 24462: invalid continuation byte

This appears to occur because the output has odd unicode characters when it imports somebody's GPG key. Here's a sample output when I run `pacman -Syu` myself (not via ansible):

http://bpaste.net/show/nFx3E9cZdgOEmv3egvt9/

(wall of text, but I believe the relevant bits are the GPG keys around lines 152-290)

This patch sanitizes the keys being thrown back to local ansible and drops out the unicode that would have otherwise bombed it out.