Revert "Have jest force exit and ignore open handles"

This reverts commit 72f4641.

Author: ewanharris

package.json

@@ -14,7 +14,7 @@
     "build": "rimraf dist && rollup -m -c --environment NODE_ENV:production && npm run test:es-check",
     "build:stats": "npm run build -- --environment WITH_STATS:true && open stats.html",
     "lint:security": "eslint ./src --ext ts --no-eslintrc --config ./.eslintrc.security",
-    "test": "jest --coverage --silent --forceExit",
+    "test": "jest --coverage --silent",
     "test:watch": "jest --coverage --watch",
     "test:debug": "node --inspect node_modules/.bin/jest --runInBand",
     "test:open:integration": "cypress open",