Add security group :zap:
diff --git a/openstack/compute/v2/extensions/secgroups/fixtures.go b/openstack/compute/v2/extensions/secgroups/fixtures.go
index d87e76b..3986eb0 100644
--- a/openstack/compute/v2/extensions/secgroups/fixtures.go
+++ b/openstack/compute/v2/extensions/secgroups/fixtures.go
@@ -9,8 +9,10 @@
 	fake "github.com/rackspace/gophercloud/testhelper/client"
 )
 
+const rootPath = "/os-security-groups"
+
 func mockListGroupsResponse(t *testing.T) {
-	th.Mux.HandleFunc("/os-security-groups", func(w http.ResponseWriter, r *http.Request) {
+	th.Mux.HandleFunc(rootPath, func(w http.ResponseWriter, r *http.Request) {
 		th.TestMethod(t, r, "GET")
 		th.TestHeader(t, r, "X-Auth-Token", fake.TokenID)
 
@@ -32,3 +34,34 @@
 `)
 	})
 }
+
+func mockCreateGroupResponse(t *testing.T) {
+	th.Mux.HandleFunc(rootPath, func(w http.ResponseWriter, r *http.Request) {
+		th.TestMethod(t, r, "POST")
+		th.TestHeader(t, r, "X-Auth-Token", fake.TokenID)
+
+		th.TestJSONRequest(t, r, `
+{
+  "security_group": {
+    "name": "test",
+    "description": "something"
+  }
+}
+	`)
+
+		w.Header().Add("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+
+		fmt.Fprintf(w, `
+{
+  "security_group": {
+    "description": "something",
+    "id": "b0e0d7dd-2ca4-49a9-ba82-c44a148b66a5",
+    "name": "test",
+    "rules": [],
+    "tenant_id": "openstack"
+  }
+}
+`)
+	})
+}