chore(package): update vue-loader to version 15.0.7

Closes #8

Author: greenkeeper[bot]

package.json

@@ -54,7 +54,7 @@
     "stylus-loader": "^3.0.1",
     "sw-precache-webpack-plugin": "^0.11.4",
     "url-loader": "^0.6.2",
-    "vue-loader": "^14.1.1",
+    "vue-loader": "^15.0.7",
     "vue-style-loader": "^4.0.2",
     "vue-template-compiler": "^2.5.3",
     "webpack": "^3.8.1",