Update site install instructions

1. Start Eclipse.
2. Start the installation procedure : select the Help -> Install New Software
3. Click Add...
4. Give a name (ie Certiv Analytics), enter the URL http://www.certiv.net/updates
5. Select this new site in the "Work with" dropdown.
6. Select plugins to install from the list and click Next.
7. Accept the terms of the license agreements and click Next.
8. Accept to restart the workbench.