Adds Mariadb-client to the Heat template

Previously, one would have to use nsenter or docker exec to
interact with the mariadb container. This patch adds mariadb
client support to the Fedora 21 instance, making it easier to
work with and test the mariadb-server container.

Change-Id: Iebfbd88b7ca6a86268e03e3e4cf4763dd46fd6a7

devenv/kollanode.yaml

@@ -184,6 +184,9 @@ resources:
             systemctl enable ntpd
             systemctl start ntpd
 
+            # Install mariadb-client
+            yum install -y mariadb
+
             # Install OpenStack Clients
             yum install -y python-keystoneclient python-glanceclient \
                            python-novaclient python-cinderclient \