[master] 1e026cf we should have graphviz to process dot files

[Nils Goroll]

commit 1e026cf611a999c775ba813fc0c89b62a72aea6f
Author: Nils Goroll <nils.goroll at uplex.de>
Date:   Tue Feb 17 12:49:23 2015 +0100

    we should have graphviz to process dot files

diff --git a/doc/sphinx/installation/install.rst b/doc/sphinx/installation/install.rst
index bbae1e6..fca2b18 100644
--- a/doc/sphinx/installation/install.rst
+++ b/doc/sphinx/installation/install.rst
@@ -88,7 +88,7 @@ installed. On a Debian or Ubuntu system these are:
 * `pkg-config`
 * `python-docutils`
 * `python-sphinx`
-
+* `graphviz`
 
 Build dependencies on Red Hat / CentOS
 --------------------------------------
@@ -108,7 +108,7 @@ packages installed:
 * `pkgconfig`
 * `python-docutils`
 * `python-sphinx`
-
+* `graphviz`
 
 Compiling Varnish
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