Integration test against Windows environment

[doodlesbykumbi]

• Add ability to integration tests against Windows environment Integration testing against puppet agents running on Windows is possible and configurable. Export the WINDOWS_DOCKER_HOST envvar to enable the Windows tests. The configurable options are available as envvars WINDOWS_DOCKER_HOST, WINDOWS_DOCKER_CERT_PATH, WINDOWS_DOCKER_TLS_VERIFY, MAIN_HOST_IP. MAIN_HOST_IP is the IP address of the host where the tests are running that should be accessible from containers running in the Windows Docker Daemon.
• Add Windows node to integration tests in Jenkins Adds a Windows 2016, with containers, node to the pipeline using the parallel stages approach for cooperation between Jenkins nodes. This provides a Windows Docker daemon for the integration tests to use

Here's an example of a run where the Windows environment is available https://asciinema.org/a/4QANgWX4IEgU6vOx9Za8TdlAl.

What does this PR do?

• What's changed? Why were these changes made?
• How should the reviewer approach this PR, especially if manual tests are required?
• Are there relevant screenshots you can add to the PR description?

What ticket does this PR close?

Connected to #[relevant GitHub issues, eg 76]

Checklists

Change log

• [ ] The CHANGELOG has been updated, or
• [ ] This PR does not include user-facing changes and doesn't require a CHANGELOG update

Test coverage

• [ ] This PR includes new unit and integration tests to go with the code changes, or
• [ ] The changes in this PR do not require tests

Documentation

• [ ] Docs (e.g. READMEs) were updated in this PR, and/or there is a follow-on issue to update docs, or
• [ ] This PR does not require updating any documentation

[izgeri]

@sgnn7 since @doodlesbykumbi is out today, can you clean up the minor nits (indenting, text suggestions, file location) and put the rest in a follow-up issue? even the file location part can go in a follow-up issue if it's going to put the build at risk of going red - I'd like to get this in and not delay any further.