Issue webcompat#977 - Added Mozilla Public License 2.0 to Package.json

Author: deepthivenkat

package.json

@@ -97,5 +97,6 @@
       "space-return-throw-case": 2,
       "space-unary-ops": 2
     }
-  }
+  },
+  "license": "MPL-2.0" 
 }