Disallow mocha .only in CI and PR validation (#516)

packages/adl/package.json

@@ -38,6 +38,7 @@
     "watch": "tsc -p . --watch",
     "dogfood": "node scripts/dogfood.js",
     "test": "mocha --timeout 5000 --require source-map-support/register --ignore 'dist/test/manual/**/*.js' 'dist/test/**/*.js'",
+    "test-official": "mocha --forbid-only --timeout 5000 --require source-map-support/register --ignore 'dist/test/manual/**/*.js' 'dist/test/**/*.js'",
     "regen-samples": "node scripts/regen-samples.js",
     "regen-nonascii": "node scripts/regen-nonascii.js",
     "fuzz": "node dist/test/manual/fuzz.js run"