Update 02_QAOA.ipynb

Author: mstechly

tutorials/02_QAOA.ipynb

@@ -44,7 +44,7 @@
    "metadata": {},
    "source": [
     "Before we can go into QAOA itself, you should prepare a couple of things:\n",
-    "1. Configure your Forest API Key - go to http://forest.rigetti.com, find section \"Get API Key\" and follow the instructions\n",
+    "1. Download and install [Forest SDK](https://qcs.rigetti.com/sdk-downloads)\n",
     "2. Install [pyQuil](https://github.com/rigetticomputing/pyquil) and [Grove](https://github.com/rigetticomputing/grove)\n",
     "3. Learn the basics of quantum computing by yourself - there are plenty of great resources about the basics in the web and I decided I don't want to reinvent the wheel in this tutorial. I recommend going to [pyQuil documentation](http://pyquil.readthedocs.io/en/stable/).\n",
     "4. You can also check out [this tutorial](https://github.com/markf94/rigetti_training_material) by guys from [ProteinQure](https://proteinqure.com). It was designed for the workshops, not self-learning, but there are many hands-on exercises and it will be a good test of your pyQuil skills :)\n",