Add DC/OS dependency installation script

Add install_imagebuild_deps which installs all the required
packages to build a DC/OS image on Ubuntu Xenial machines.

Change-Id: I85c48d91ff0750d90358056a09287dfc1c12faf2
Partially-Implements: blueprint mesos-dcos

contrib/drivers/dcos_centos_v1/image/install_imagebuild_deps.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+
+# This script installs all needed dependencies to generate
+# images using diskimage-builder. Please note it only has been
+# tested on Ubuntu Xenial.
+
+set -eux
+set -o pipefail
+
+sudo apt update || true
+sudo apt install -y \
+    git \
+    qemu-utils \
+    python-dev \
+    python-yaml \
+    python-six \
+    uuid-runtime \
+    curl \
+    sudo \
+    kpartx \
+    parted \
+    wget \
+    xfsprogs \
+    yum \
+    yum-utils