updating npm dependencies to avoid security vulnerability

package.json

@@ -16,8 +16,8 @@
   "license": "MIT",
   "devDependencies": {
     "chai": "^4.1.2",
-    "copy-webpack-plugin": "^4.3.0",
-    "css-loader": "^0.28.7",
+    "copy-webpack-plugin": "^4.5.0",
+    "css-loader": "^0.28.10",
     "cwd": "^0.10.0",
     "karma": "^1.7.1",
     "karma-chai": "^0.1.0",
@@ -25,20 +25,20 @@
     "karma-mocha-reporter": "^2.2.5",
     "karma-phantomjs-launcher": "^1.0.4",
     "karma-sinon": "^1.0.5",
-    "karma-webpack": "^2.0.9",
-    "mocha": "^4.0.1",
+    "karma-webpack": "^2.0.13",
+    "mocha": "^4.1.0",
     "node-sass": "^4.7.2",
     "phantomjs-prebuilt": "^2.1.16",
     "rimraf": "^2.6.2",
-    "sass-loader": "^6.0.6",
-    "sinon": "^4.1.3",
+    "sass-loader": "^6.0.7",
+    "sinon": "^4.4.2",
     "style-loader": "^0.19.1",
     "tfx-cli": "^0.4.16",
-    "ts-loader": "^3.2.0",
-    "typescript": "^2.6.2",
+    "ts-loader": "^3.5.0",
+    "typescript": "^2.7.2",
     "typings": "^2.1.1",
-    "webpack": "^3.10.0",
-    "webpack-dev-server": "^2.9.7"
+    "webpack": "^3.11.0",
+    "webpack-dev-server": "^2.11.2"
   },
   "dependencies": {
     "vss-web-extension-sdk": "^2.117.0"