Techometer reporting

[Westbrook]

Expected Behaviour

Tachometer scoring is applied somewhere and covers a decent amount of an elements standard use cases?

Actual Behaviour

You have to run it manually.

Reproduce Scenario (including but not limited to)

npm run test:bench

Notes:

Be sure to check on things like #103 (comment) when deciding how to cover use cases.

[Westbrook]

Looks like the change to have lit-html be a dependency rather than a devDependency a la https://github.com/adobe/spectrum-web-components/pull/683/files#diff-62e26ea604f25c999ecde6acf4720099R48 would allow us to leverage the --package-version flag from tachometer to compare @current to a local build of the packages, which would allow us to leverage this scoring in CI and possibly as a PR gate. Another great win for #679.

[Westbrook]

With the addition of #978 we'll be able to efficiently test a local build against what's on the latest channel on NPM. Steps from there to see this completed:

• test performance changes in CI (possibly filtering for changes similar to what the Lerna versioning code does)
• report results into PRs
• possibly block PRs with regressions behind an approval step