Merge branch 'update_installation_doc_python_docutils' into 'master'

Update installation doc with python-docutils

Fixes #1293

doc/install/installation.md

@@ -49,7 +49,7 @@ up-to-date and install it.
 
 Install the required packages (needed to compile Ruby and native extensions to Ruby gems):
 
-    sudo apt-get install -y build-essential zlib1g-dev libyaml-dev libssl-dev libgdbm-dev libreadline-dev libncurses5-dev libffi-dev curl openssh-server redis-server checkinstall libxml2-dev libxslt-dev libcurl4-openssl-dev libicu-dev logrotate
+    sudo apt-get install -y build-essential zlib1g-dev libyaml-dev libssl-dev libgdbm-dev libreadline-dev libncurses5-dev libffi-dev curl openssh-server redis-server checkinstall libxml2-dev libxslt-dev libcurl4-openssl-dev libicu-dev logrotate python-docutils
 
 Make sure you have the right version of Git installed
 
@@ -336,9 +336,7 @@ Visit YOUR_SERVER in your web browser for your first GitLab login. The setup has
 
 ### Additional markup styles
 
-Apart from the always supported markdown style there are other rich text files that GitLab can display. But you might have to install a dependency to do so. Please see the [github-markup gem readme](https://github.com/gitlabhq/markup#markups) for more information. For example, reStructuredText markup language support requires python-docutils:
-
-    sudo apt-get install -y python-docutils
+Apart from the always supported markdown style there are other rich text files that GitLab can display. But you might have to install a dependency to do so. Please see the [github-markup gem readme](https://github.com/gitlabhq/markup#markups) for more information.
 
 ### Custom Redis Connection