fix allow import json files

Author: Carlos Rufo

tsconfig.json

@@ -6,7 +6,8 @@
     "sourceMap": true,
     "experimentalDecorators": true,
     "emitDecoratorMetadata": true,
-    "esModuleInterop": true
+    "esModuleInterop": true,
+    "resolveJsonModule": true
   },
   "include": ["src/**/*"],
   "exclude": ["node_modules", "dist", "**/*.spec.ts"]