We recently started using python to run some tests. The usage of a
common shared file creates compiled python modules in pycache
directory. Ignore this and any other compiled python files.
The patch should not do harm and seems to be useful to some, so I am approving it. Although I think it is redundant (that is, most of the entries in this file) with what the top-level .gitignore already contains.
Adding a trailing / indicates to git to apply the rules to directories.