Merge branch 'STF525' of https://forge.etsi.org/gitlab/ITS/ITS into STF525

README.md

@@ -37,7 +37,28 @@ The ETSI ITS protocols project builds and tests regularly on the following platf
 
   - Linux (Ubuntu)
 
-Note: The [OpenSSL](https://www.openssl.org) version > 1.x is also required.
+Note: The [OpenSSL](https://www.openssl.org) version > 1.1.x is also required.
+
+### How to do it?
+
+They are two different methods:
+- Using [Vagrant](https://www.vagrantup.com/)
+- Using [Docker](https://www.docker.com/)
+
+How to choose one of these methods is depending of your host system.
+
+NOTE: In all case, if you want to setup an continuous integration process (e.g. Jenkins), Docker is the best choice. 
+
+
+#### The host system is Windows
+The both methods require a virtual machine. You can use either VirtualBox or WMware.
+In this case, the easiest way is to use Vagrant.
+
+
+#### The host system is Linux
+Vagrant requires a virtual machine. You can use either VirtualBox or WMware.
+Docker does not need a virtual machine, so it is the more efficant way.
+
 
 ### Using Vagrant