Fix CI Pipeline and Opt-in to Meta Tests

[PlagueHO]

Pull Request (PR) description

This PR fixes the CI Pipeline by pinning Pester to 4.10.1. It also corrects the URLs for the Dev build badge and opts in to the meta tests:

• Common Tests - Custom Script Analyzer Rules.
• Common Tests - Flagged Script Analyzer Rules.
• Common Tests - New Error-Level Script Analyzer Rules.
• Common Tests - Relative Path Length.
• Common Tests - Required Script Analyzer Rules.
• Common Tests - Validate Markdown Links.
• Common Tests - Validate Markdown Files.

This Pull Request (PR) fixes the following issues

• Fixes #199
• Fixes #172

Task list

• [x] Added an entry under the Unreleased section in the CHANGELOG.md. Entry should say what was changed, and how that affects users (if applicable).
• [ ] Resource documentation added/updated in README.md.
• [ ] Resource parameter descriptions added/updated in README.md, schema.mof and comment-based help.
• [ ] Comment-based help added/updated.
• [ ] Localization strings added/updated in all localization files as appropriate.
• [ ] Examples appropriately added/updated.
• [ ] Unit tests added/updated. See DSC Resource Testing Guidelines.
• [ ] Integration tests added/updated (where possible). See DSC Resource Testing Guidelines.
• [x] New/changed code adheres to DSC Resource Style Guidelines and Best Practices.

@johlju - would you mind reviewing for me when you get time? I'd like to at least have CI process working on this module. cc @mgreenegit

[codecov-commenter]

Codecov Report

Merging #200 (c4481ab) into dev (7064eda) will not change coverage. The diff coverage is 33%.

@@         Coverage Diff         @@
##            dev   #200   +/-   ##
===================================
  Coverage    82%    82%           
===================================
  Files        19     19           
  Lines      2760   2760           
  Branches      4      4           
===================================
  Hits       2270   2270           
  Misses      486    486           
  Partials      4      4           

[johlju]

@PlagueHO I rather @mgreenegit look and review this PR. Btw. integration tests seems to fail.

[PlagueHO]

I think the integration tests are failing because of the AppVeyor agent version (using a really old one). They pass when I specify recent version of agent (VS2019). But I can't check because I don't have access to the PowerShell AppVeyor config. Could probably set the agent version in the AppVeyor CI config though.