updated the external link

README.rst

@@ -4,7 +4,7 @@ high-complexity computing applications, enable code and data reuse and
 provenance, provide methods for validation and error tracking, and exploit 
 application concurrency using distributed computing resources. The goal of this 
 tutorial is to learn composing and running workflow applications using the 
-FireWorks workflow environment (https://pythonhosted.org/FireWorks/). In the 
+FireWorks workflow environment (https://hackingmaterials.lbl.gov/fireworks). In the 
 first part, after an introduction to the concept of workflows, to 
 state-of-the-art workflow systems and to FireWorks, the participants will learn 
 to construct workflows using a library of existing Firetasks. The composed