Replace fasteners dependency to filelock

[yuxuanzhuang]

We replaced Fastener with Filelock in MDAnalysis/mdanalysis#4800.

We need to update UserGuide installation guide

[orbeckst]

@namiroues does your PR #404 fix this issue?

[orbeckst]

https://userguide.mdanalysis.org/stable/contributing_code.html uses filelock, so this has been fixed