Add auth support (#21)

* Updates

* Update

* Update

* Update

* Update

* Yarn sometimes prefers npmrc, so use same token

* Description

* Update readme

* Feedback

* Add type

* new toolkit and scoped registries

* npmrc in RUNNER_TEMP

* Dont always auth

* Try exporting blank token

* Get auth working for now pending runner changes

* Fix string interpolation for auth token.

* Don't export both userconfigs

* Update authutil.js

* Add single quotes for authString

* Fix the registry string.

* Use userconfig and append trailing slash

* Keep in root of repo

* Try just adding auth token

* Remove auth token

* Try changes again

* Add tests

* Npm and GPR samples

* Add types

node_modules/isexe/package.json

@@ -0,0 +1,64 @@
+{
+  "_args": [
+    [
+      "isexe@2.0.0",
+      "C:\\Users\\Administrator\\Documents\\setup-node"
+    ]
+  ],
+  "_development": true,
+  "_from": "isexe@2.0.0",
+  "_id": "isexe@2.0.0",
+  "_inBundle": false,
+  "_integrity": "sha1-6PvzdNxVb/iUehDcsFctYz8s+hA=",
+  "_location": "/isexe",
+  "_phantomChildren": {},
+  "_requested": {
+    "type": "version",
+    "registry": true,
+    "raw": "isexe@2.0.0",
+    "name": "isexe",
+    "escapedName": "isexe",
+    "rawSpec": "2.0.0",
+    "saveSpec": null,
+    "fetchSpec": "2.0.0"
+  },
+  "_requiredBy": [
+    "/which"
+  ],
+  "_resolved": "https://registry.npmjs.org/isexe/-/isexe-2.0.0.tgz",
+  "_spec": "2.0.0",
+  "_where": "C:\\Users\\Administrator\\Documents\\setup-node",
+  "author": {
+    "name": "Isaac Z. Schlueter",
+    "email": "i@izs.me",
+    "url": "http://blog.izs.me/"
+  },
+  "bugs": {
+    "url": "https://github.com/isaacs/isexe/issues"
+  },
+  "description": "Minimal module to check if a file is executable.",
+  "devDependencies": {
+    "mkdirp": "^0.5.1",
+    "rimraf": "^2.5.0",
+    "tap": "^10.3.0"
+  },
+  "directories": {
+    "test": "test"
+  },
+  "homepage": "https://github.com/isaacs/isexe#readme",
+  "keywords": [],
+  "license": "ISC",
+  "main": "index.js",
+  "name": "isexe",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/isaacs/isexe.git"
+  },
+  "scripts": {
+    "postpublish": "git push origin --all; git push origin --tags",
+    "postversion": "npm publish",
+    "preversion": "npm test",
+    "test": "tap test/*.js --100"
+  },
+  "version": "2.0.0"
+}