switch to ncc files (#44)

package.json

@@ -2,9 +2,9 @@
     "name": "setup-kubectl-action",
     "version": "0.0.0",
     "private": true,
-    "main": "lib/run.js",
+    "main": "lib/index.js",
     "scripts": {
-        "build": "tsc --outDir ./lib --rootDir ./src",
+        "build": "ncc build src/run.ts -o lib",
         "test": "jest",
         "test-coverage": "jest --coverage"
     },
@@ -22,9 +22,10 @@
     },
     "devDependencies": {
         "@types/node": "^12.0.4",
+        "@vercel/ncc": "^0.33.1",
         "jest": "^26.0.1",
         "@types/jest": "^25.2.2",
         "ts-jest": "^25.5.1",
         "typescript": "3.9.2"
     }
-}
+}