fix: Karma not exiting in a single run

The ng update didn't update angular.json file to point to the
@Angular-devkit package for karma. I must have googled something to fix
it in 77df8ef but only managed to install the package and not actually
tell angular.json to use it. This change makes it so that we are
building with a version of karma that allows run once (and matches what
template you get using the ng new command)

closes #84

Author: ProgrammingByPermutation

src/angular.json

@@ -84,7 +84,7 @@
           }
         },
         "test": {
-          "builder": "@angular/build:karma",
+          "builder": "@angular-devkit/build-angular:karma",
           "options": {
             "polyfills": [
               "zone.js",
@@ -101,7 +101,7 @@
               "src/styles.scss"
             ],
             "scripts": [],
-            "karmaConfig": "karma.conf.js"
+            "karmaConfig": "karma.conf.prod.js"
           }
         },
         "lint": {