Added dh-make to Dockerfile

Change-Id: Ia154dd507ea99605e0a504230705f2ccaf3192c4
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/Dockerfile b/Dockerfile
index f028c0f..2cb64d0 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -7,5 +7,5 @@
 FROM ubuntu:16.04
 
 RUN apt-get update && apt-get -y install git make libcurl4-gnutls-dev \
-    libgnutls-dev debhelper apt-utils
+    libgnutls-dev debhelper apt-utils dh-make