ASCII characters are not supported

While doing an amulet test, it fails if there as an ASCII character in the metadata.yaml file. Not sure if this happens in the config.yaml file too, but it fails if there is one in the metadata.yaml file with the following error:

Traceback (most recent call last):
  File "tests/100_deploy.test", line 21, in <module>
    d.add('owncloud', units=scale)
  File "/usr/lib/python3/dist-packages/amulet/deployer.py", line 66, in add
    c = get_charm(os.getcwd())
  File "/usr/lib/python3/dist-packages/amulet/charm.py", line 111, in get_charm
    return LocalCharm(charm_path)
  File "/usr/lib/python3/dist-packages/amulet/charm.py", line 127, in __init__
    self._raw = self._load(os.path.join(path, 'metadata.yaml'))
  File "/usr/lib/python3/dist-packages/amulet/charm.py", line 140, in _load
    data = yaml.safe_load(f.read())
  File "/usr/lib/python3.4/encodings/ascii.py", line 26, in decode
    return codecs.ascii_decode(input, self.errors)[0]
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 311: ordinal not in range(128)
juju-test.conductor.100_deploy.test RESULT : ✘