problems found by Sonatype Lift scan

[XSpielinbox]

When running Sonatype Lift on this repository, it finds 52 problems that can be viewed online.

I don't know how good/helpful these results are, but they might be worth to look at and fix them.

[jtesta]

@XSpielinbox : thanks for letting me know! I've fixed most of the problems found by Shellcheck in 953683a.

As a note to myself, the following tools made some additional findings that may be worth looking into:

• https://github.com/microsoft/pyright
• https://github.com/facebook/pyre-check
• https://github.com/PyCQA/bandit

[XSpielinbox]

Glad to hear!