Merge branch 'master' into 'master'

Modification de la section installation de Vagrant

See merge request !2

content/slides/cri/md/vagrant.md

@@ -29,19 +29,13 @@
 ## Installation
 
 pré-requis
+VirtualBox (versions 4.0.x, 4.1.x, 4.2.x, 4.3.x, 5.0.x, 5.1.x, 5.2.x)
 
 ```
 $ sudo apt install virtualbox
 ```
 
-via gem
-
-```
-$ sudo apt install rubygems-integration
-$ sudo gem install vagrant
-```
-
-via apt
+install via apt (plus distribué via RubyGem)
 
 ```
 $ sudo apt install vagrant