Use the cache-bindep element on dib nodes

We intend to use bindep to tell us what distro packages should be
installed at job run-time, so need to similarly identify those in
such a way that they can be cached on our worker images.

Install the cache-bindep element on all diskimage-builder based
nodepool images, so that we will have bindep available to jobs which
need it along with a cache of the distro packages they might
require.

Note that similar tooling is not applied to snapshot nodes, since we
only intend to run jobs which use bindep on diskimage-builder
created nodes.

Change-Id: I22b39f5117bb78d387414668c63df135cbc53243
Depends-On: I0c408fee35dfe9b4f700c51565bfaae0a3d03beb

modules/openstack_project/templates/nodepool/nodepool.yaml.erb

@@ -939,6 +939,7 @@ diskimages:
       - puppet
       - nodepool-base
       - node-devstack
+      - cache-bindep
     env-vars:
       TMPDIR: /opt/dib_tmp
       DIB_IMAGE_CACHE: /opt/dib_cache
@@ -951,6 +952,7 @@ diskimages:
       - puppet
       - nodepool-base
       - node-devstack
+      - cache-bindep
     release: trusty
     env-vars:
       TMPDIR: /opt/dib_tmp
@@ -963,6 +965,7 @@ diskimages:
       - puppet
       - nodepool-base
       - node-devstack
+      - cache-bindep
     release: trusty
     env-vars:
       TMPDIR: /opt/dib_tmp
@@ -976,6 +979,7 @@ diskimages:
       - puppet
       - nodepool-base
       - node-devstack
+      - cache-bindep
     release: precise
     env-vars:
       TMPDIR: /opt/dib_tmp
@@ -989,6 +993,7 @@ diskimages:
       - puppet
       - nodepool-base
       - node-devstack
+      - cache-bindep
     env-vars:
       TMPDIR: /opt/dib_tmp
       DIB_IMAGE_CACHE: /opt/dib_cache
@@ -1001,6 +1006,7 @@ diskimages:
       - puppet
       - nodepool-base
       - node-devstack
+      - cache-bindep
     release: 21
     env-vars:
       TMPDIR: /opt/dib_tmp