Change HTTP methods for OpenStack CDN
diff --git a/openstack/cdn/v1/services/requests.go b/openstack/cdn/v1/services/requests.go
index 85a73ed..8b37928 100644
--- a/openstack/cdn/v1/services/requests.go
+++ b/openstack/cdn/v1/services/requests.go
@@ -177,9 +177,7 @@
 	}
 
 	// Send request to API
-	resp, err := c.Request("POST", createURL(c), gophercloud.RequestOpts{
-		JSONBody: &reqBody,
-	})
+	resp, err := c.Post(createURL(c), &reqBody, nil, nil)
 	res.Header = resp.Header
 	res.Err = err
 	return res
@@ -198,9 +196,7 @@
 	}
 
 	var res GetResult
-	_, res.Err = c.Request("GET", url, gophercloud.RequestOpts{
-		JSONResponse: &res.Body,
-	})
+	_, res.Err = c.Get(url, &res.Body, nil)
 	return res
 }
 
@@ -377,6 +373,6 @@
 	}
 
 	var res DeleteResult
-	_, res.Err = c.Request("DELETE", url, gophercloud.RequestOpts{})
+	_, res.Err = c.Delete(url, nil)
 	return res
 }