Make a note that FloydHub is optional for image classification project

Author: mcleonard

image-classification/README.md

@@ -1,4 +1,6 @@
-## Running the Udacity Deep Learning Foundations image classification project on floydhub.com
+## (Optional) Running the Udacity Deep Learning Foundations image classification project on floydhub.com
+
+You are not required to use FloydHub for this project, but we've provided instructions if you'd like help getting set up.
 
 1. Create an account on [floydhub.com](https://www.floydhub.com) (don't forget to confirm your email). Create an individual account on floydhub.com (don't forget to confirm your email). (You won’t be able to finish most projects in the one hour allowed for free trials). Prices for floydhub.com are currently $0.432 / hour of GPU use, and most of your projects will run in around 2 - 3 hours. In order to minimize cost, you may want to try to both debug as much as possible on your local computer and make sure that you end your jobs soon after they finish.