[ONOS-2225] Implement REST API for Flow Objectives

This commit implements REST API for Flow Objective Service.
The corresponding unit test will be followed in a separated commit.

Change-Id: I94d1dc6cfc07fc9d07fcf8c303c8e395b40ed122
diff --git a/web/api/src/main/resources/definitions/NextId.json b/web/api/src/main/resources/definitions/NextId.json
new file mode 100644
index 0000000..5dcc8e8
--- /dev/null
+++ b/web/api/src/main/resources/definitions/NextId.json
@@ -0,0 +1,14 @@
+{
+  "type": "object",
+  "title": "nextId",
+  "required": [
+    "id"
+  ],
+  "properties": {
+    "nextId": {
+      "type": "integer",
+      "format": "int64",
+      "example": 3
+    }
+  }
+}
\ No newline at end of file