Allow disabling fcntl (and use softfilelock) with environment variable #289
Description
I'm using a cluster and the home directory is a network volume that has fcntl disabled.
filelock/src/filelock/_unix.py
Lines 25 to 31 in 481daa4
filelock currently selects fcntl whenever the library is available, ignoring its availability on the file system.
NotImplementedError: FileSystem does not appear to support flock; user SoftFileLock instead
Adding an environment or some other way to control this behavior would be better.