Infrastructure guide is stale + minor code analysis review

[dcamron]

What can be better?

#3870 found a broken link to codeclimate, which now lives under the name qlty.sh. This revealed to me we have a link to Codacy, which hasn't analyzed any of our commits or PRs in 3+ years.

1. Do we update and use the new codeclimate service?
2. Do we revive Codacy?
3. The infrastructure guide has a few other minor incorrect references. It's worth a brush-up.

[dopplershift]

Looks like Code Climate spun out their code quality division/service last November. Logging into the previous code climate site shows:

so something has to happen. I'll turn off code climate and turn on qlty and see if we like the results.

I've reinstalled the Codacy webhook and we can see what it triggers.