Replace .npmignore with "files": [...] in package.json

Author: lydell

.npmignore

@@ -21,6 +21,12 @@
     "coffee": "./bin/coffee",
     "cake": "./bin/cake"
   },
+  "files": [
+    "bin",
+    "lib",
+    "register.js",
+    "repl.js"
+  ],
   "preferGlobal": true,
   "scripts": {
     "test":         "node ./bin/cake test",