2.7.0 doesn't work under Windows

[scottwday]

This commit added a dependency on fcntl which isn't present in Windows.

Resulting in ModuleNotFoundError: No module named 'fcntl'

I can create a PR to exclude it, but would this issue be present in Windows too?

[eht16]

Already reported (#82) and fixed in master. Will be released later today.

I don't know if Windows is also affected by #81. If so, PRs are welcome but I won't work on this myself.