Make `now link` great again (#573)

* `link` directory to run `npm link` inside

* since `lib` is default source dir name for js (`src` is mostly c++)

* fix linting

* Revert "since `lib` is default source dir name for js (`src` is mostly c++)"

This reverts commit 799edd4e717e66f763593636e7fbbe4b5df239a6.

* Added script for linking

link/link.js

@@ -0,0 +1,3 @@
+#!/usr/bin/env node
+// eslint-disable-next-line import/no-unassigned-import
+require('../bin/now.js');

link/package.json

@@ -0,0 +1,6 @@
+{
+  "name": "now",
+  "bin": {
+    "now": "link.js"
+  }
+}

package.json

@@ -8,6 +8,7 @@
     "postinstall": "node download/install.js",
     "precommit": "xo --quiet && lint-staged",
     "prepublish": "in-install || (npm run webpack && cp /dev/null download/dist/now)",
+    "link": "cd link && npm link",
     "lint": "xo --quiet",
     "test": "npm run lint && ava",
     "pack": "pkg bin/now.js -c package.json -o packed/now",