Move diskimage-builder to infra

Per http://git.openstack.org/cgit/openstack/governance/commit/?id=44f092fac580a65037b5a4a406b0f11cb7d08eee

Change-Id: I100a0485593cf618ee734c965f0ed6c30ad87e86

projects/infra.json

@@ -1,6 +1,8 @@
 {
     "name": "OpenStack Infrastructure",
     "subprojects": [
+        "openstack/dib-utils",
+        "openstack/diskimage-builder",
         "openstack-dev/openstack-nose",
         "openstack-infra/activity-board",
         "openstack-infra/ansible-build-image",

projects/tripleo.json

@@ -1,7 +1,5 @@
 {"name": "tripleo", "subprojects": [
     "openstack-infra/tripleo-ci",
-    "openstack/dib-utils",
-    "openstack/diskimage-builder",
     "openstack/instack",
     "openstack/instack-undercloud",
     "openstack/os-apply-config",
@@ -23,7 +21,6 @@
 ],
     "core-team-gerrit-group": "tripleo-core",
 "lp_projects": [
-    "diskimage-builder",
     "os-apply-config",
     "os-cloud-config",
     "os-collect-config",