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/npm-run-path/index.js

@@ -0,0 +1,39 @@
+'use strict';
+const path = require('path');
+const pathKey = require('path-key');
+
+module.exports = opts => {
+	opts = Object.assign({
+		cwd: process.cwd(),
+		path: process.env[pathKey()]
+	}, opts);
+
+	let prev;
+	let pth = path.resolve(opts.cwd);
+	const ret = [];
+
+	while (prev !== pth) {
+		ret.push(path.join(pth, 'node_modules/.bin'));
+		prev = pth;
+		pth = path.resolve(pth, '..');
+	}
+
+	// ensure the running `node` binary is used
+	ret.push(path.dirname(process.execPath));
+
+	return ret.concat(opts.path).join(path.delimiter);
+};
+
+module.exports.env = opts => {
+	opts = Object.assign({
+		env: process.env
+	}, opts);
+
+	const env = Object.assign({}, opts.env);
+	const path = pathKey({env});
+
+	opts.path = env[path];
+	env[path] = module.exports(opts);
+
+	return env;
+};