fix(package): update sass-loader to version 7.0.1

Closes #91

Author: greenkeeper[bot]

package.json

@@ -41,7 +41,7 @@
     "node-sass": "^4.5.3",
     "postcss-loader": "^2.0.5",
     "sanitize.css": "^5.0.0",
-    "sass-loader": "^6.0.5",
+    "sass-loader": "^7.0.1",
     "standard": "^11.0.0",
     "style-loader": "^0.20.0",
     "webpack": "^3.0.0"