Updates HACKING.rst with information about setting up the front-end testing framework.
Updates HACKING.rst with information about setting up the front-end testing framework.

Solinea/goldstone-server,slashk/goldstone-server,slashk/goldstone-server,slashk/goldstone-server,Solinea/goldstone-server,Solinea/goldstone-server,slashk/goldstone-server,Solinea/goldstone-server,slashk/goldstone-server,Solinea/goldstone-server