Automatically start web UI in ray.init(). (#687)

* Start up webui on ray.init

* Removed .ipynb checkpoint folders.

* Removed print statements in cleanup function.

* Fixed

* Removed extra file.

* Cleaned up ui.

* Don't start browser automatically in ray.init(), also copy the notebook every time so that changes don't persist.

* Update setup.py and installation instructions to install jupyter.

* Don't automatically install jupyter, don't start the UI if jupyter is not installed.

* Improve error message when failing to start UI.

python/ray/WebUI.ipynb

@@ -0,0 +1,47 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Evaluate the box below to initialize the web UI."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "import os\n",
+    "import ray\n",
+    "\n",
+    "redis_address = os.environ[\"REDIS_ADDRESS\"]\n",
+    "ray.init(redis_address=redis_address)"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.6.0"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}