add 'files' to package.json

package.json

@@ -3,6 +3,10 @@
     "version": "3.0.0",
     "description": "FileSytem-based Manager with optional encrypted Cloud backup for Greenlock SSL",
     "main": "manager.js",
+    "files": [
+        "*.js",
+        "lib"
+    ],
     "scripts": {
         "test": "node tests"
     },