Feature/filestorage securityservices list (#134)

* sfs: Add support for security services List

* sfs: Add acceptance tests for security service List

* sfs: Remove extra parameters for security service list

After taking a closer look at the code, some parameters
seem to be filtered out during the list request. They
have now been filtered out.

* sfs: Fix unit tests

* sfs: Use SecurityServiceType for ListOpts Type
diff --git a/openstack/sharedfilesystems/v2/securityservices/testing/fixtures.go b/openstack/sharedfilesystems/v2/securityservices/testing/fixtures.go
index e6b101a..c6b5f70 100644
--- a/openstack/sharedfilesystems/v2/securityservices/testing/fixtures.go
+++ b/openstack/sharedfilesystems/v2/securityservices/testing/fixtures.go
@@ -58,3 +58,80 @@
 		w.WriteHeader(http.StatusAccepted)
 	})
 }
+
+func MockListResponse(t *testing.T) {
+	th.Mux.HandleFunc("/security-services/detail", func(w http.ResponseWriter, r *http.Request) {
+		th.TestMethod(t, r, "GET")
+		th.TestHeader(t, r, "X-Auth-Token", fake.TokenID)
+
+		w.Header().Add("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+
+		fmt.Fprintf(w, `
+        {
+            "security_services": [
+                {
+                    "status": "new",
+                    "domain": null,
+                    "project_id": "16e1ab15c35a457e9c2b2aa189f544e1",
+                    "name": "SecServ1",
+                    "created_at": "2015-09-07T12:19:10.000000",
+                    "description": "Creating my first Security Service",
+                    "updated_at": null,
+                    "server": null,
+                    "dns_ip": "10.0.0.0/24",
+                    "user": "demo",
+                    "password": "supersecret",
+                    "type": "kerberos",
+                    "id": "3c829734-0679-4c17-9637-801da48c0d5f"
+                },
+                {
+                    "status": "new",
+                    "domain": null,
+                    "project_id": "16e1ab15c35a457e9c2b2aa189f544e1",
+                    "name": "SecServ2",
+                    "created_at": "2015-09-07T12:25:03.000000",
+                    "description": "Creating my second Security Service",
+                    "updated_at": null,
+                    "server": null,
+                    "dns_ip": "10.0.0.0/24",
+                    "user": null,
+                    "password": null,
+                    "type": "ldap",
+                    "id": "5a1d3a12-34a7-4087-8983-50e9ed03509a"
+                }
+            ]
+        }`)
+	})
+}
+
+func MockFilteredListResponse(t *testing.T) {
+	th.Mux.HandleFunc("/security-services/detail", func(w http.ResponseWriter, r *http.Request) {
+		th.TestMethod(t, r, "GET")
+		th.TestHeader(t, r, "X-Auth-Token", fake.TokenID)
+
+		w.Header().Add("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+
+		fmt.Fprintf(w, `
+        {
+            "security_services": [
+                {
+                    "status": "new",
+                    "domain": null,
+                    "project_id": "16e1ab15c35a457e9c2b2aa189f544e1",
+                    "name": "SecServ1",
+                    "created_at": "2015-09-07T12:19:10.000000",
+                    "description": "Creating my first Security Service",
+                    "updated_at": null,
+                    "server": null,
+                    "dns_ip": "10.0.0.0/24",
+                    "user": "demo",
+                    "password": "supersecret",
+                    "type": "kerberos",
+                    "id": "3c829734-0679-4c17-9637-801da48c0d5f"
+                }
+            ]
+        }`)
+	})
+}