[PR] Enable LGTM checks and fix few LGTM alerts

[kopf-archiver]

A pull request by nolar at 2020-01-29 16:12:53+00:00
Original URL: zalando-incubator/kopf#302
Merged by nolar at 2020-01-30 15:04:54+00:00

What do these changes do?

Improve the codebase to resolve the remaining LGTM's warnings and some of the recommendations.

LGTM itself is enabled via GitHub actions/integrations, so no code changes are needed.

Description

LGMT is a code quality control tool (one of them) — as in "looks good to me": https://lgtm.com/

This project's analysis can be previewed at https://lgtm.com/projects/g/zalando-incubator/kopf/

The code logic is changed in few places — presumably, with no behavioural changes (just try-except-else restructuring to a flat code).

Issues/PRs

Issues: #13

Type of changes

• Mostly CI/CD automation, contribution experience

Checklist

• The code addresses only the mentioned problem, and this problem only
• I think the code is well written
• Unit tests for the changes exist
• Documentation reflects the changes
• If you provide code modification, please add yourself to CONTRIBUTORS.txt