Enable all tests and remove unmaintained istanbul code coverage tool

package.json

@@ -82,7 +82,6 @@
   "devDependencies": {
     "expect.js": "*",
     "hock": "^1.3.3",
-    "istanbul": "*",
     "js2xmlparser": "^4.0.0",
     "mocha": "^6.1.3",
     "mock-aws-s3": "git+https://github.com/cloudron-io/mock-aws-s3.git",
@@ -92,7 +91,7 @@
     "sinon": "^7.3.1"
   },
   "scripts": {
-    "test": "src/test/setupTest && BOX_ENV=test ./node_modules/istanbul/lib/cli.js test $1 ./node_modules/mocha/bin/_mocha -- --no-timeouts --exit -R spec ./src/test ./src/routes/test/[^a]*js",
+    "test": "runTests",
     "postmerge": "/bin/true",
     "precommit": "/bin/true",
     "prepush": "npm test",