(SIMP-10204) Ensure Testing with Centos 8.4 (#81)

- update the EL8 nodes in the acceptance tests
    to run with generic/centos8 to make sure they using
    CentOS 8.4
  - update oel7 nodeset to generic from onyxpoint

SIMP-10204 #comment aide updated
SIMP-10207 #close

spec/acceptance/nodesets/default.yml

@@ -9,7 +9,6 @@ HOSTS:
   el7:
     roles:
       - client
-      # roles migrated from now-removed el6 node(s): 
       - server
       - default
       - master
@@ -21,7 +20,7 @@ HOSTS:
     roles:
       - client
     platform: el-8-x86_64
-    box: centos/8
+    box: generic/centos8
     hypervisor: <%= hypervisor %>
 
 CONFIG:

spec/acceptance/nodesets/oel.yml

@@ -9,12 +9,12 @@ HOSTS:
   oel7:
     roles:
       - client
-      # roles migrated from now-removed el6 node(s): 
+      # roles migrated from now-removed el6 node(s):
       - server
       - default
       - master
     platform: el-7-x86_64
-    box: onyxpoint/oel-7-x86_64
+    box: generic/oracle7
     hypervisor: <%= hypervisor %>
 
   oel8: