build: update karma-coverage-istanbul-reporter to version ~2.1.0

Author: renovate-bot

packages/angular_devkit/build_angular/package.json

@@ -78,7 +78,7 @@
     "jasmine-spec-reporter": "~4.2.1",
     "karma": "~4.2.0",
     "karma-chrome-launcher": "~2.2.0",
-    "karma-coverage-istanbul-reporter": "~2.0.0",
+    "karma-coverage-istanbul-reporter": "~2.1.0",
     "karma-jasmine": "~2.0.1",
     "karma-jasmine-html-reporter": "^1.4.0",
     "popper.js": "^1.14.1",