starting on core

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@actions/core",
-  "version": "1.0.0",
+  "version": "0.1.0",
   "description": "Actions core lib",
   "keywords": [
     "core",
@@ -30,5 +30,8 @@
   },
   "bugs": {
     "url": "https://github.com/actions/toolkit/issues"
+  },
+  "devDependencies": {
+    "@types/node": "^12.0.2"
   }
 }