Allow more recent versions of dependencies

[damonmaria]

What does this PR do?

Allow latest versions of: stdlib, concat, apt

Motivation

This module is blocking us from using the most recent versions of these.

Describe your test plan

Assuming low chance of impact. CI tests will pick up any issues.

[damonmaria]

Note that the latest versions of these 3 modules all require at least Puppet 6.

[mx-psi]

👋 looks like our tests are in bad shape, I opened #729 to fix (most of) them. Please stay put until we merge this (or cherry-pick the commit if you prefer that :) )

[damonmaria]

@mx-psi Thanks. As per my note above, depending on how the Puppet version requirement of these dependencies are enforced the tests on Puppet < 6.1 may fail.

[mx-psi]

It should be safe to rebase now, we have some flaky tests but otherwise everything should pass eventually

@mx-psi Thanks. As per my note above, depending on how the Puppet version requirement of these dependencies are enforced the tests on Puppet < 6.1 may fail.

We need to keep support for Puppet 4 and Puppet 5 for now, since we have users using these versions, even if they are EOL. I think this change will be fine for tests given that the range we already have contains versions incompatible with Puppet 4 or Puppet 5 in some cases but, in any case, we will test installation once tests pass to double check.