Update Karma dependencies to latest versions

package.json

@@ -80,16 +80,16 @@
     "grunt-contrib-uglify": "^3.4.0",
     "grunt-contrib-watch": "^1.0.0",
     "grunt-eslint": "^21.0.0",
-    "grunt-karma": "^2.0.0",
+    "grunt-karma": "^3.0.2",
     "grunt-mocha-test": "^0.13.3",
     "grunt-run": "^0.8.1",
-    "karma": "^1.1.2",
-    "karma-browserify": "^5.1.1",
-    "karma-chrome-launcher": "^1.0.1",
+    "karma": "^4.1.0",
+    "karma-browserify": "^6.0.0",
+    "karma-chrome-launcher": "^2.2.0",
     "karma-es6-shim": "^1.0.0",
     "karma-firefox-launcher": "^1.0.0",
     "karma-html2js-preprocessor": "^1.0.0",
-    "karma-junit-reporter": "~1.0.0",
+    "karma-junit-reporter": "^1.2.0",
     "karma-mocha": "^1.1.1",
     "karma-script-launcher": "^1.0.0",
     "loopback-boot": "^2.7.0",