Proposal: Automated Tests

[jugglinmike]

I'd like to write some tests for test file content. As a start, these would
assert:

• Valid YAML frontmatter syntax
• Basic frontmatter tag requirements
  • Presence of description tag
  • Valid configurations
    • Mutual exclusivity of strictOnly and noStrict
    • At least one of es5id and es6id
• Presence of copyright block

These assertions are admittedly a little weak, but even superficial checks like
these would have prevented past errors (e.g. gh-177, gh-225, gh-144). Because
test262 does not currently offer any automated tests, this work would involve
introducing the tooling and practices. That would reduce the friction in
implementing more substantial/helpful tests in the future (see for instance,
gh-276 and gh-297).

This will require some discussion about dependencies, but I wanted to see if
the basic proposal is desired before getting into technical details.

[jugglinmike]

This could also enforce a restriction on description length that is currently requested in the project's contribution guidelines.

[leobalter]

#546 will have us one step closer to solve this.

The items you have listed here sound reasonable to me.

[rwaldron]

This was addressed by implementing a linter that runs in our CI