banner raises errors

[flying-sheep]

when doing

aiomanhole.start_manhole(namespace={'server': something}, path='/var/tmp/testing.manhole')

this is raised:

ERROR:asyncio:Exception in callback <bound method StreamReaderProtocol.connection_made of <asyncio.streams.StreamReaderProtocol object at 0x7fadbb4c4ef0>>(<asyncio.selector_events._SelectorSocketTransport object at 0x7fadbb4c4cc0>,)
handle: Handle(<bound method StreamReaderProtocol.connection_made of <asyncio.streams.StreamReaderProtocol object at 0x7fadbb4c4ef0>>, (<asyncio.selector_events._SelectorSocketTransport object at 0x7fadbb4c4cc0>,))
Traceback (most recent call last):
  File "/usr/lib/python3.4/asyncio/events.py", line 39, in _run
    self._callback(*self._args)
  File "/usr/lib/python3.4/asyncio/streams.py", line 212, in connection_made
    self._stream_writer)
  File "/usr/lib/python3.4/site-packages/aiomanhole/__init__.py", line 211, in __call__
    **self.kwargs
  File "/usr/lib/python3.4/site-packages/aiomanhole/__init__.py", line 50, in __init__
    self.banner = banner if isinstance(banner, bytes) else banner.encode('utf8')
AttributeError: 'NoneType' object has no attribute 'encode'

[nhoad]

Thanks for the report! This is fixed in 0.2.1, available on PyPI now :)