Issue with output on windows

[MichaelLogutov]

Running on windows it seems execute returns some invalid characters in output and thus failing on getting port from output (and maybe somewhere else).

I've managed to patch this like this:

`
from lovely.pytest.docker import compose

def strip_invalid_characters_from_output(func):
def wrapper(*args, **kwargs):
output = func(*args, **kwargs)
return output[:output.rfind('\n') + 1]

return wrapper

compose.execute = strip_invalid_characters_from_output(compose.execute)
`