fix format-yaml to work with python 3

Change-Id: I48717815536a4e31fbac799f7fc7743ff8bc3c4d
Signed-off-by: Doug Hellmann <doug@doughellmann.com>

openstack_releases/cmds/reformat_yaml.py

@@ -23,10 +23,10 @@ def main():
     args = parser.parse_args()
     for filename in args.file:
         print("Reformatting %s" % filename)
-        with open(filename, 'rb') as fh:
+        with open(filename, 'r', encoding='utf-8') as fh:
             contents = yamlutils.loads(fh.read())
         contents = yamlutils.dumps(contents)
-        with open(filename, 'wb') as fh:
+        with open(filename, 'w', encoding='utf-8') as fh:
             fh.write(contents)
             if not contents.endswith("\n"):
                 fh.write("\n")

openstack_releases/yamlutils.py

@@ -90,11 +90,13 @@ for str_type in [six.binary_type, six.text_type]:
 
 def dumps(obj):
     """Dump a python object -> blob and apply our pretty styling."""
-    buff = six.BytesIO()
+    buff = six.StringIO()
     yaml.dump_all([obj], buff,
-                  explicit_start=True, indent=2,
+                  explicit_start=True,
+                  indent=2,
                   default_flow_style=False,
-                  line_break="\n", Dumper=PrettySafeDumper,
+                  line_break="\n",
+                  Dumper=PrettySafeDumper,
                   allow_unicode=True)
     return buff.getvalue()