Use timeago format in Latest Start column of the Sync Log

[mathjazz]

As discussed on Slack...

Deployed to stage:
https://mozilla-pontoon-staging.herokuapp.com/sync/

[eemeli]

A few concerns:

1. It's not clear what a "month" is? Is it exactly four weeks, or something else? It would probably be better to go from days to weeks to years.
2. Why is the change only applied to the listing of all projects' most recent sync events, and not the errors view or the project-specific views?
3. As discussed on Slack, it would probably be best to explicitly use and show (with a trailing Z) UTC timestamps for all non-relative times.

[mathjazz]

It's not clear what a "month" is? Is it exactly four weeks, or something else? It would probably be better to go from days to weeks to years.

Yeah, that's how Django works for this feature and it's used across the app already.

Why is the change only applied to the listing of all projects' most recent sync events, and not the errors view or the project-specific views?

The answer is simple and straighforward: I forgot.

As discussed on Slack, it would probably be best to explicitly use and show (with a trailing Z) UTC timestamps for all non-relative times.

I added UTC. I wasn't aware of Z(ulu).