Fix docker-compose-check Hook

[Matthew-Grayson]

🗣 Description

Add .env setup step to build.yml: addresses error by docker-compose-check hook.

💭 Motivation and context

The docker-compose-check hook relies on variables stored in a .env file. This file wasn't available in the GitHub Actions test environment, so I added a step to create it in the lint job.
Closes issue #108

🧪 Testing

All unit tests pass.
docker-compose-check hook passes.

✅ Pre-approval checklist

• This PR has an informative and human-readable title.
• Changes are limited to a single goal - eschew scope creep!
• All future TODOs are captured in issues, which are referenced
  in code comments.
• All relevant type-of-change labels have been added.
• I have read the CONTRIBUTING document.
• These code changes follow cisagov code standards.
• All relevant repo and/or project documentation has been updated
  to reflect the changes in this PR.
• Tests have been added and/or modified to cover the changes in this PR.
• All new and existing tests pass.

✅ Pre-merge checklist

• Revert dependencies to default branches.
• Finalize version.

✅ Post-merge checklist

• Create a release.

[cduhn17]

LGTM

[dav3r]

I'm confused when you say:

Merging this and PR #48 fixes the only remaining failing pre-commit hooks.

First of all, #48 is an issue, not a PR. Did you mean PR #49, which resolved issue #48?

Second, this PR still shows those two JSON-related pre-commit hooks failing. If those JSON hooks were passing thanks to the changes in #49, why are those changes not included in this PR? If they were, then the build / lint tests in this PR should pass.

[Matthew-Grayson]

I'm confused when you say:

Merging this and PR #48 fixes the only remaining failing pre-commit hooks.

First of all, #48 is an issue, not a PR. Did you mean PR #49, which resolved issue #48?

Second, this PR still shows those two JSON-related pre-commit hooks failing. If those JSON hooks were passing thanks to the changes in #49, why are those changes not included in this PR? If they were, then the build / lint tests in this PR should pass.

I've since merged develop into this branch and updated the PR language to reflect that all pre-commit hooks pass.

[dav3r]

👍 👍