Remove dependency on py

[camara-tech]

The py library has been marked in maintenance mode, and has a known security vulnerability. https://nvd.nist.gov/vuln/detail/CVE-2022-42969

I successfully ran the tests on python 2.7 and python 3.10 to verify that removing this dependency doesn't require any code changes.

Fixes #58

[tisba]

Having a known security vulnerability is such a PITA, even if they are not used but just reported by tools 🙄 If you require certain compliance processes, this creates so much unnecessary and annoying work 😞

It would be so awesome, if you could consider merging and releasing this, @invl! 🙏

[robinbowes]

If py is not used, it seems like a no-brainer to remove the dependency. Would also fix #58

Another vote for this PR 😃

[robinbowes]

I've done some further investigation.

py contains four tools/modules:

• py.path: uniform local and svn path objects -> please use pathlib/pathlib2 instead
• py.apipkg: explicit API control and lazy-importing -> please use the standalone package instead
• py.iniconfig: easy parsing of .ini files -> please use the standalone package instead
• py.code: dynamic code generation and introspection (deprecated, moved to pytest as a implementation detail).

Prior to the 1.4 release, it also used to contain py.test which is now its own package, see https://docs.pytest.org

retry only uses py.test, which is now provided by pytest.

It is safe to remove the py dependency.

[CraigKnottAtlassian]

If this works and passes test can a maintainer merge and release this please? @invl