Add ruby install in doc

diff --git a/README.rst b/README.rst
index d69d46f8fc127e8ff8644eaf9f556331211541c4..2f5bf3e591677eec5cd1c07686378030461e5ede 100644 (file)
--- a/README.rst
+++ b/README.rst
@@ -79,6 +79,7 @@ Gulp require nodejs installed on your computer to work.
 
 4. Install ruby dependencies::
 
+    sudo apt install ruby
     sudo gem install bundler
     bundle install