Add git to the image Dockerfile as well

We use a `git` based reference to the `em-common` repo.
The related PR added git to the test dockerfile
#965
to get the tests to pass.

We need to add a similar command to the production Dockerfile

Dockerfile

@@ -8,7 +8,7 @@ WORKDIR /usr/src/app
 RUN apt-get -y -qq update
 RUN apt-get install -y -qq curl
 RUN apt-get install -y -qq wget
-# RUN apt-get install -y git
+RUN apt-get install -y -qq git
 
 # install nano and vim for editing
 # RUN apt-get -y install nano vim