Remove "repository" from package.json (#63)

I considered fixing it instead but it also seem pretty redundant. Anyone
using this package is going to already know where it comes from and we
are not publishing it on npm (since its private it cannot live in npm)

Author: sbc100

package.json

@@ -9,10 +9,6 @@
     "build": "tsc && ncc build lib/main.js --license licenses.txt",
     "test": "ava"
   },
-  "repository": {
-    "type": "git",
-    "url": "git+https://github.com/actions/node12-template.git"
-  },
   "keywords": [
     "actions",
     "node",