Add Unleash json schema

ee/spec/fixtures/api/schemas/unleash/unleash.json

+{
+  "additionalProperties": false,
+  "properties": {
+    "features": {
+      "items": {
+        "$ref": "unleash_feature.json"
+      },
+      "minItems": 0,
+      "type": "array"
+    },
+    "version": {
+      "type": "integer"
+    }
+  },
+  "required": [
+    "version",
+    "features"
+  ],
+  "type": "object"
+}

ee/spec/fixtures/api/schemas/unleash/unleash_feature.json

+{
+  "type": "object",
+  "additionalProperties": false,
+  "required": [
+    "name",
+    "enabled"
+  ],
+  "properties": {
+    "name": {
+      "type": "string"
+    },
+    "enabled": {
+      "type": "boolean"
+    },
+    "description": {
+      "type": "string"
+    }
+  }
+}

ee/spec/requests/api/unleash_spec.rb

@@ -75,8 +75,7 @@ describe API::Unleash do
         subject
         
         expect(response).to have_gitlab_http_status(:ok)
-
-        # TODO: match schema
+        expect(response).to match_response_schema('unleash/unleash', dir: 'ee')
       end
     end
   end