Add tests and fixes for rehydration

* Barracks must get an initial state or state.location is undefined
* Replaces document.addEventListener w/ pkg handling existing ready doc

tests/browser/rehydration.js

@@ -0,0 +1,28 @@
+const test = require('tape')
+const onReady = require('document-ready')
+const choo = require('../../')
+const view = require('../../html')
+
+test('rehydration', function (t) {
+  t.plan(2)
+
+  const app = choo()
+
+  app.router((route) => [
+    route('/', function (state, prev, send) {
+      return view`<div id="app-root" onclick=${() => send('test')}>Hello world!</span>`
+    })
+  ])
+
+  var node = document.createElement('div')
+  node.innerHTML = app.toString('/')
+  node = node.childNodes[0]
+  document.body.appendChild(node)
+
+  app.start('#app-root')
+
+  onReady(function () {
+    t.equal(node.innerHTML, 'Hello world!', 'same content')
+    t.equal(typeof node.onclick, 'function', 'attaches dom listeners')
+  })
+})