Remove support for erroneous host_vars and group_vars

These are now host-vars and group-vars.

Change-Id: I68ccb922cdc58f40bf0bf02614de78fdb17976b4
diff --git a/tests/fixtures/config/ansible/git/common-config/zuul.yaml b/tests/fixtures/config/ansible/git/common-config/zuul.yaml
index 13a19da..abd77ec 100644
--- a/tests/fixtures/config/ansible/git/common-config/zuul.yaml
+++ b/tests/fixtures/config/ansible/git/common-config/zuul.yaml
@@ -138,10 +138,10 @@
             - host3
     vars:
       allvar: all
-    host_vars:
+    host-vars:
       host1:
         hostvar: host
-    group_vars:
+    group-vars:
       group1:
         groupvar: group
 
diff --git a/zuul/configloader.py b/zuul/configloader.py
index 60c335c..d3f3236 100644
--- a/zuul/configloader.py
+++ b/zuul/configloader.py
@@ -512,8 +512,6 @@
                       'roles': to_list(role),
                       'required-projects': to_list(vs.Any(job_project, str)),
                       'vars': dict,
-                      'host_vars': {str: dict},
-                      'group_vars': {str: dict},
                       'host-vars': {str: dict},
                       'group-vars': {str: dict},
                       'dependencies': to_list(str),
@@ -750,14 +748,14 @@
                 raise Exception("Variables named 'zuul' or 'nodepool' "
                                 "are not allowed.")
             job.variables = variables
-        host_variables = conf.get('host-vars', conf.get('host_vars', None))
+        host_variables = conf.get('host-vars', None)
         if host_variables:
             for host, hvars in host_variables.items():
                 if 'zuul' in hvars or 'nodepool' in hvars:
                     raise Exception("Variables named 'zuul' or 'nodepool' "
                                     "are not allowed.")
             job.host_variables = host_variables
-        group_variables = conf.get('group-vars', conf.get('group_vars', None))
+        group_variables = conf.get('group-vars', None)
         if group_variables:
             for group, gvars in group_variables.items():
                 if 'zuul' in group_variables or 'nodepool' in gvars: