Make jest bail out (#918)

Currently the CI tests take around 5-7 minutes and are failing
regularly. The error usually occurs during one of the first check
suites but we still run all tests before reporting the error. In order
shorten the feedback cycle, I added the --bail flag to the test command
to make sure CI reports errors immediately.

package.json

@@ -3,7 +3,7 @@
   "license": "MIT",
   "scripts": {
     "start": "node --max-semi-space-size=64 ./lib/run.js",
-    "test": "node --expose-gc --max-old-space-size=4096 ./node_modules/.bin/jest --coverage --runInBand --logHeapUsage --forceExit",
+    "test": "node --expose-gc --max-old-space-size=4096 ./node_modules/.bin/jest --coverage --runInBand --logHeapUsage --bail --forceExit",
     "test:watch": "node --expose-gc --max-old-space-size=4096 ./node_modules/.bin/jest --runInBand --logHeapUsage --forceExit --watch --notify",
     "posttest": "npm run lint",
     "lint": "eslint lib test",