Add keystone and neutron config classes and codec with unit tests

Change-Id: Ia89f5be9bac88927a383d56d56413ba23e3e5eb3
diff --git a/apps/openstacknode/api/src/main/java/org/onosproject/openstacknode/api/NeutronConfig.java b/apps/openstacknode/api/src/main/java/org/onosproject/openstacknode/api/NeutronConfig.java
new file mode 100644
index 0000000..86ea2a9
--- /dev/null
+++ b/apps/openstacknode/api/src/main/java/org/onosproject/openstacknode/api/NeutronConfig.java
@@ -0,0 +1,67 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.openstacknode.api;
+
+/**
+ * Representation of openstack neutron config information.
+ */
+public interface NeutronConfig {
+
+    /**
+     * Returns whether to use metadata proxy service.
+     * Note that SONA will behave as a metadata proxy server
+     *
+     * @return true if metadata proxy service is enabled, false otherwise
+     */
+    boolean useMetadataProxy();
+
+    /**
+     * Returns metadata proxy secret.
+     *
+     * @return metadata proxy secret
+     */
+    String metadataProxySecret();
+
+    /**
+     * Builder of neutron config.
+     */
+    interface Builder {
+
+        /**
+         * Builds an immutable neutron config instance.
+         *
+         * @return neutron config instance
+         */
+        NeutronConfig build();
+
+        /**
+         * Returns neutron config with supplied useMetadataProxy flag.
+         *
+         * @param useMetadataProxy useMetadataProxy flag
+         * @return neutron config builder
+         */
+        Builder useMetadataProxy(boolean useMetadataProxy);
+
+        /**
+         * Returns neutron config with supplied metadataProxySecret.
+         *
+         * @param metadataProxySecret metadata proxy secret
+         * @return neutron config builder
+         */
+        Builder metadataProxySecret(String metadataProxySecret);
+    }
+}