Merge ~ltrager/maas-images:centos1905 into maas-images:master

[Lee Trager]

Bump CentOS to 1905

Tested in the CI. All machines deploy CentOS 7, CentOS 6 only supports legacy booting and deployed on all legacy systems.

[Newell Jensen (newell-jensen)]

+1

review: Approve

diff --git a/conf/centos.yaml b/conf/centos.yaml
index 854782d..6f410f9 100644
--- a/conf/centos.yaml
+++ b/conf/centos.yaml
@@ -15,10 +15,10 @@ versions:
         curtin_files: "{curtin_path}/centos7"
         # The upstream revision to create MAAS images for. All other versions
         # are ignored if this is defined.
-        revision: 1901
+        revision: 1905
         # The lp:maas-images release. This defaults to 01. Changing this will
         # cause a new build of the revision to be imported.
-        release: 01
+        # release: 01
         packages:
          # cloud-init depends on packages from EPEL
          - epel-release
@@ -59,10 +59,10 @@ versions:
         curtin_files: "{curtin_path}/centos6"
         # The upstream revision to create MAAS images for. All other versions
         # are ignored if this is defined.
-        revision: 1808
+        revision: 1905
         # The lp:maas-images release. This defaults to 01. Changing this will
         # cause a new build of the revision to be imported.
-        release: 02
+        # release: 02
         packages:
          # cloud-init depends on packages from EPEL
          - epel-release