Security issues (inject, plexus, mojos)

[cstamas]

Now that dependabot is enabled, we have Security issues (see tab at top line) across all 3 repositories (inject, plexus, mojos).

They are usually:

• logback (wants 1.2.13+)
• maven core (wants 3.8.1+)
• junit (wants 4.12.3)

I think is fine if we up them.

@kwin @mcculls

[cstamas]

Merged what I wanted, things remaining are mostly these in this issue.

[cstamas]

Fixed with latest commits.