standardize indentation at 2 spaces

Update the linter rules to require 2 spaces. Update our dumper to emit
2 spaces.

Change-Id: Idef3574021845bccfc92c75425bc0f40b32b0026
Signed-off-by: Doug Hellmann <doug@doughellmann.com>

openstack_releases/yamlutils.py

@@ -78,6 +78,13 @@ class PrettySafeDumper(yaml.dumper.SafeDumper):
         else:
             return super(PrettySafeDumper, self).represent_undefined(data)
 
+    # Override this method to always indent. Otherwise when a list is
+    # emitted, the items nested under it are not and we have inconsistent
+    # formatting.
+    # https://stackoverflow.com/questions/25108581/python-yaml-dump-bad-indentation
+    def increase_indent(self, flow=False, indentless=False):
+        return super(PrettySafeDumper, self).increase_indent(flow, False)
+
 
 # NOTE(harlowja): at some point this may not be needed...
 # See: http://pyyaml.org/ticket/29

yamllint.yml

@@ -7,3 +7,7 @@ rules:
     max: 200
     level: warning
     allow-non-breakable-words: true
+
+  indentation:
+    spaces: 2
+