Exposed embedded key existence in HalResource, added a test to check …

[jguittard]

Provide a narrative description of what you are trying to accomplish:

• Are you fixing a bug?
  • Detail how the bug is invoked currently.
  • Detail the original, incorrect behavior.
  • Detail the new, expected behavior.
  • Base your feature on the master branch, and submit against that branch.
  • Add a regression test that demonstrates the bug, and proves the fix.
  • Add a CHANGELOG.md entry for the fix.

See #52 for details

[weierophinney]

This repository has been closed and moved to mezzio/mezzio-hal; a new issue has been opened at mezzio/mezzio-hal#3.

[weierophinney]

This repository has been moved to mezzio/mezzio-hal. If you feel that this patch is still relevant, please re-open against that repository, and reference this issue. To re-open, we suggest the following workflow:

• Squash all commits in your branch (git rebase -i origin/{branch})
• Make a note of all changed files (`git diff --name-only origin/{branch}...HEAD
• Run the laminas/laminas-migration tool on the code.
• Clone mezzio/mezzio-hal to another directory.
• Copy the files from the second bullet point to the clone of mezzio/mezzio-hal.
• In your clone of mezzio/mezzio-hal, commit the files, push to your fork, and open the new PR.
  We will be providing tooling via laminas/laminas-migration soon to help automate the process.