Concat requirement version bump

[den-is]

Recently concat has been updated to v4.0.0

Warning: Module 'puppetlabs-concat' (v4.0.0) fails to meet some dependencies:
  'datadog-datadog_agent' (v1.10.0) requires 'puppetlabs-concat' (v2.2.0)

Good to have something like

    {
      "name": "puppetlabs/concat",
      "version_requirement": ">=2.2.0 <5.0.0"
    }

[truthbk]

@den-is if memory serves me well, we pinned to a specific concat version because concat 4.0.0 breaks stuff for older puppet versions (ie. <4). I'll give the latest concat module a whirl, just in case it fixes existing issues, but otherwise we might have to keep this pinned until the next major release.

[ColinHebert]

@truthbk FWIW Puppet 5 is now out, dropping support of puppet 3 doesn't seem like a bad idea

[truthbk]

@ColinHebert we'll probably do that with the release of a new major release. I would like to do a few things in that release - chiefly make the classes more resource-like and less include-like.... but that might be more work than anticipated.

We definitely have got this in mind!!

[bittner]

This dependency is creating a load of issues in our control repo.

Please drop support for Puppet < 4 and upgrade the version requirement.

[den-is]

This module has really slow development pace, while this is not opensource product.
I'm thinking of dropping it from my env, and writing my own.
Coz dd-agent is not something complex, like nginx or haproxy for example, where you really have benefits of using well build puppet module.
I just need to install package and have only one stupid integration file.