PID/Hostname File Locking for Cluster Environments.

The PID file locking ecosystem in Python may not be robust to the networked filesystems common to HPC clusters, which may have multiple hosts on multiple operating systems.

Quoting @amilsted:
> Julia core uses https://github.com/vtjnash/Pidfile.jl to do hostname/PID-based locking to https://github.com/JuliaLang/julia/issues/42405 and https://github.com/JuliaLang/julia/issues/42405, because this type of locking is https://github.com/JuliaLang/julia/issues/31953.

A successful fix for this issue would identify and integrate a python pidfile implementation which offers the same (tested) guarantees as https://github.com/vtjnash/Pidfile.jl. Further discussion in https://github.com/JuliaPy/pyjuliapkg/pull/45, where FileLock may be used as an interim solution.