REF: Rename LICENSE.txt -> LICENSE [skip ci]

package.json

@@ -2,7 +2,7 @@
   "name": "g1",
   "version": "0.9.0",
   "description": "Gramex 1.x interaction library",
-  "license": "UNLICENSED",
+  "license": "MIT",
   "author": "S Anand <s.anand@gramener.com>",
   "main": "index.js",
   "repository": {