Whitelist package files

package.json

@@ -3,6 +3,18 @@
   "version": "8.2.4",
   "description": "Run a command using sudo, prompting the user with an OS dialog if necessary",
   "main": "index.js",
+  "files": [
+    "CHANGELOG.md",
+    "LICENSE",
+    "README.md",
+    "index.js",
+    "linux.png",
+    "macos.png",
+    "package.json",
+    "test-concurrent.js",
+    "test.js",
+    "windows.png"
+  ],
   "repository": {
     "type": "git",
     "url": "git+https://github.com/jorangreef/sudo-prompt.git"