Metal3: Add parameters for mariadb

Parameters for using mariadb and for building the mariadb container
image in metal3-dev-env.
Configure the integration test on mariadb-image to actually use mariadb.

Change-Id: I8cd383961a06fb391a4fbaa12c1a86644568203e
diff --git a/jjb/metal3/projects.yml b/jjb/metal3/projects.yml
index 4431392..b662c7f 100644
--- a/jjb/metal3/projects.yml
+++ b/jjb/metal3/projects.yml
@@ -78,6 +78,8 @@
           repo: ironic-ipa-downloader
       - mariadb_image:
           repo: mariadb-image
+          build_mariadb_image_locally: 'true'
+          ironic_use_mariadb: 'true'
     image_os:
       - ubuntu
       - centos