refactored DecodeHeader function to gophercloud package; updated tests
diff --git a/openstack/objectstorage/v1/containers/results.go b/openstack/objectstorage/v1/containers/results.go
index 4c27ec6..66939fa 100644
--- a/openstack/objectstorage/v1/containers/results.go
+++ b/openstack/objectstorage/v1/containers/results.go
@@ -120,7 +120,7 @@
 		return gh, gr.Err
 	}
 
-	if err := mapstructure.Decode(gr.Header, &gh); err != nil {
+	if err := gophercloud.DecodeHeader(gr.Header, &gh); err != nil {
 		return gh, err
 	}
 
@@ -174,7 +174,7 @@
 		return ch, cr.Err
 	}
 
-	if err := mapstructure.Decode(cr.Header, &ch); err != nil {
+	if err := gophercloud.DecodeHeader(cr.Header, &ch); err != nil {
 		return ch, err
 	}
 
@@ -212,7 +212,7 @@
 		return uh, ur.Err
 	}
 
-	if err := mapstructure.Decode(ur.Header, &uh); err != nil {
+	if err := gophercloud.DecodeHeader(ur.Header, &uh); err != nil {
 		return uh, err
 	}
 
@@ -250,7 +250,7 @@
 		return dh, dr.Err
 	}
 
-	if err := mapstructure.Decode(dr.Header, &dh); err != nil {
+	if err := gophercloud.DecodeHeader(dr.Header, &dh); err != nil {
 		return dh, err
 	}