Update hard-source-webpack-plugin to the latest version 🚀 (#182)

Author: greenkeeper[bot]

package.json

@@ -46,7 +46,7 @@
     "express-jwt": "^5.3.0",
     "express-promise-router": "^3.0.1",
     "extract-text-webpack-plugin": "^3.0.1",
-    "hard-source-webpack-plugin": "^0.5.14",
+    "hard-source-webpack-plugin": "^0.6.0",
     "history": "^4.7.2",
     "html-webpack-plugin": "^3.0.0",
     "jsonwebtoken": "^8.1.0",