OSS cleanup

[lukasmalkmus]

The usual procedure:

• README
• Makefile & tooling, linters, etc.
• CI/CD, automated releases, Docker images, etc.

I also addressed the linter issues. However, one test is failing. Not because of my change, tests were not passing for main, either. One interesting thing: After I addressed the linter issues, the test still failed, but on another assertion. I'm not familiar with the code and the failure is not particularly related to my changes. Someone please double-check before merging. /cc @bahlo

For reference:

=== Failed
=== FAIL: parser TestParseTestSuite/TestParse (0.01s)
    parse_test.go:494: 
            Error Trace:    parse_test.go:494
            Error:          Not equal: 
                            expected: 2006
                            actual  : 2021
            Test:           TestParseTestSuite/TestParse
            Messages:       <7>1 2006-10-29T01:59:59.156+01:00 mymachine.example.com evntslog - ID47 [exampleSDID@0 iut="3" eventSource="Application" eventID="1011"][examplePriority@0 class="high"]  An application event log entry...
    --- FAIL: TestParseTestSuite/TestParse (0.01s)

=== FAIL: parser TestParseTestSuite (0.02s)

Before my linter fixes it was:

parse_test.go:497: 
                Error Trace:    parse_test.go:497
                Error:          Not equal: 
                                expected: 5
                                actual  : 4
                Test:           TestParseTestSuite/TestParse
                Messages:       <6> Mar  7 05:45:39 eth systemd[1]: Starting Message of the Day...

[seiflotfy]

cc @seiflotfy re test failure

on it

[bahlo]

@lukasmalkmus CodeCov is broken