remove default=None for config options

In the config module default=None is set as the default value,
it isn't necessary to set it again when doing config options.

Change-Id: Id6bbdb3c6b23bcc31d7a02057a73729e89cabb5c
Closes-Bug: #1323975

magnum/common/clients.py

@@ -29,7 +29,6 @@ LOG = logging.getLogger(__name__)
 
 magnum_client_opts = [
     cfg.StrOpt('region_name',
-               default=None,
                help=_('Region in Identity service catalog to use for '
                       'communication with the OpenStack service.')),
     cfg.StrOpt('endpoint_type',
@@ -40,7 +39,6 @@ magnum_client_opts = [
 
 heat_client_opts = [
     cfg.StrOpt('region_name',
-               default=None,
                help=_('Region in Identity service catalog to use for '
                       'communication with the OpenStack service.')),
     cfg.StrOpt('endpoint_type',
@@ -62,7 +60,6 @@ heat_client_opts = [
 
 glance_client_opts = [
     cfg.StrOpt('region_name',
-               default=None,
                help=_('Region in Identity service catalog to use for '
                       'communication with the OpenStack service.')),
     cfg.StrOpt('endpoint_type',
@@ -73,7 +70,6 @@ glance_client_opts = [
 
 barbican_client_opts = [
     cfg.StrOpt('region_name',
-               default=None,
                help=_('Region in Identity service catalog to use for '
                       'communication with the OpenStack service.')),
     cfg.StrOpt('endpoint_type',
@@ -84,7 +80,6 @@ barbican_client_opts = [
 
 nova_client_opts = [
     cfg.StrOpt('region_name',
-               default=None,
                help=_('Region in Identity service catalog to use for '
                       'communication with the OpenStack service.')),
     cfg.StrOpt('endpoint_type',

magnum/conductor/handlers/bay_conductor.py

@@ -47,7 +47,6 @@ bay_heat_opts = [
                help=('Sleep time interval between two attempts of querying '
                      'the Heat stack.  This interval is in seconds.')),
     cfg.IntOpt('bay_create_timeout',
-               default=None,
                help=('The length of time to let bay creation continue.  This '
                      'interval is in minutes.  The default is no timeout.'))
 ]

magnum/conductor/template_definition.py

@@ -49,7 +49,6 @@ template_def_opts = [
                default='https://discovery.etcd.io/new?size=%(size)d',
                help=_('Url for etcd public discovery endpoint.')),
     cfg.StrOpt('coreos_discovery_token_url',
-               default=None,
                deprecated_name='discovery_token_url',
                deprecated_group='bay_heat',
                help=_('coreos discovery token url.')),
@@ -59,7 +58,6 @@ template_def_opts = [
                help=_('Location of template to build a swarm '
                       'cluster on atomic.')),
     cfg.StrOpt('swarm_discovery_url_format',
-               default=None,
                help=_('Format string to use for swarm discovery url. '
                       'Available values: bay_id, bay_uuid. '
                       'Example: "etcd://etcd.example.com/\%(bay_uuid)s"')),