Issue 6890 - run npm tests in parallel (PENDING)

package.json

 {
   "name": "adblockpluschrome",
   "repository": "https://hg.adblockplus.org/adblockpluschrome",
   "license": "GPL-3.0",
   "dependencies": {},
   "devDependencies": {
     "//": [
       "'dmg', 'extract-zip' and 'ncp' are needed by `download_*.js` modules",
       "in adblockpluscore/test/.",
       "The chromedriver version was pinned to that exact version, due to",
       "incompatibilities with the configured chromium version and newer",
       "drivers."

[tlucas, 2018/09/03 09:54:46]

Result of rebasing.

     ],
     "chromedriver": "2.36.0",
     "dmg": "^0.1.0",
     "eslint": "^5.1.0",
     "eslint-config-eyeo": "^2.1.0",
     "extract-zip": "^1.6.5",
     "geckodriver": "^1.9.0",
     "ncp": "^2.0.0",
     "mocha": "^5.2.0",
     "selenium-webdriver": "^3.6.0"
   },
   "scripts": {
     "pretest": "python ensure_dependencies.py",
     "lint": "eslint *.js lib/ qunit/ ext/ test/",
-    "test": "mocha",
-    "posttest": "npm run lint"

[Sebastian Noack, 2018/09/03 19:37:36]

Perhaps we can leave this in here, and then in the CI configuration run
"npm run test" (instead of "npm test"). This should run just the "test" script
(but not "pretest" and "posttest"). The advantage is that when running "npm
test" during development, it would still lint, and the "pretest" step here is
redundant anyway with the CI. What do you think?

[tlucas, 2018/09/03 21:35:54]

Unfortunately it doesn't matter, whether one invokes "npm run test" or "npm
test" - pre-/posttest are always invoked (at least with node v8.11.4). I assume
it's merely convenience, to be able to leave out "run" here.

[Sebastian Noack, 2018/09/03 21:57:47]

I guess we could add another script, e.g. test-only.

[tlucas, 2018/09/04 07:19:36]

Right! Done.

+    "test": "mocha"
   }
 }