update less and less loader

Author: chnbohwr

package-lock.json

@@ -27,8 +27,8 @@
     "file-loader": "^0.9.0",
     "gh-pages": "^1.0.0",
     "html-webpack-plugin": "^2.28.0",
-    "less": "^2.7.1",
-    "less-loader": "^2.2.3",
+    "less": "^3.0.1",
+    "less-loader": "^4.1.0",
     "node-sass": "^4.5.3",
     "null-loader": "^0.1.1",
     "postcss": "^6.0.19",