change all time fields to have type time.Time (#190)

* add Volume.Unmarshal

* add volumetenants.VolumeExt.Unmarshal

* create servers.Server time.Time fields

* json.Unmarshal can correctly handle time.RFC3339 (Server time fields)

* add v3 Token UnmarshalJSON method

* check for empty string when unmarshaling time

* add Member UnmarshalJSON

* v3 tokens.Token ExtractInto

* v3 trust.Trust UnmarshalJSON

* time.Time fields swift response objects

* time.Time fields for orchestration response objects

* time.Time fields for shared file systems response objects

* if we don't use pointers for the custom time fields, we don't need to check if they're nil

* style guide fixes: 'r' for receiver, 's' for struct

* remove unnecessary pointers from UnmarshalJSON methods
diff --git a/openstack/objectstorage/v1/objects/testing/fixtures.go b/openstack/objectstorage/v1/objects/testing/fixtures.go
index 53f03f5..08faab8 100644
--- a/openstack/objectstorage/v1/objects/testing/fixtures.go
+++ b/openstack/objectstorage/v1/objects/testing/fixtures.go
@@ -8,7 +8,6 @@
 	"testing"
 	"time"
 
-	"github.com/gophercloud/gophercloud"
 	"github.com/gophercloud/gophercloud/openstack/objectstorage/v1/objects"
 	th "github.com/gophercloud/gophercloud/testhelper"
 	fake "github.com/gophercloud/gophercloud/testhelper/client"
@@ -32,14 +31,14 @@
 var ExpectedListInfo = []objects.Object{
 	{
 		Hash:         "451e372e48e0f6b1114fa0724aa79fa1",
-		LastModified: gophercloud.JSONRFC3339MilliNoZ(time.Date(2016, time.August, 17, 22, 11, 58, 602650000, time.UTC)), //"2016-08-17T22:11:58.602650"
+		LastModified: time.Date(2016, time.August, 17, 22, 11, 58, 602650000, time.UTC), //"2016-08-17T22:11:58.602650"
 		Bytes:        14,
 		Name:         "goodbye",
 		ContentType:  "application/octet-stream",
 	},
 	{
 		Hash:         "451e372e48e0f6b1114fa0724aa79fa1",
-		LastModified: gophercloud.JSONRFC3339MilliNoZ(time.Date(2016, time.August, 17, 22, 11, 58, 602650000, time.UTC)),
+		LastModified: time.Date(2016, time.August, 17, 22, 11, 58, 602650000, time.UTC),
 		Bytes:        14,
 		Name:         "hello",
 		ContentType:  "application/octet-stream",