Add ssh key to Dockerfile.production for tests

Change-Id: I1849a8170779b29e88af515c0d7c2b41694e6130
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/Dockerfile.production b/Dockerfile.production
index 4f8b516..5fffd7d 100644
--- a/Dockerfile.production
+++ b/Dockerfile.production
@@ -149,4 +149,6 @@
 ENV LC_ALL=C.UTF-8
 ENV LANG=C.UTF-8
 
-ENTRYPOINT [ "/robot-systest/run_test.sh"]
+RUN cat /dev/zero | ssh-keygen -t rsa -q -N "" > /dev/null
+
+ENTRYPOINT [ "/bin/sh" ]