fix class hardcode to pet (#3014)

Author: wing328

modules/openapi-generator/src/main/resources/dart-jaguar/model_test.mustache

@@ -5,7 +5,7 @@ import 'package:test/test.dart';
 
 // tests for {{classname}}
 void main() {
-  var instance = new Pet();
+  var instance = new {{classname}}();
 
   group('test {{classname}}', () {
     {{#vars}}

modules/openapi-generator/src/main/resources/dart/model_test.mustache

@@ -5,7 +5,7 @@ import 'package:test/test.dart';
 
 // tests for {{classname}}
 void main() {
-  var instance = new Pet();
+  var instance = new {{classname}}();
 
   group('test {{classname}}', () {
     {{#vars}}

samples/client/petstore/dart-jaguar/flutter_petstore/openapi/README.md

@@ -4,7 +4,7 @@ This is a sample server Petstore server. For this sample, you can use the api ke
 This Dart package is automatically generated by the [Open API Codegen](https://github.com/OpenAPITools/openapi-generator) project:
 
 - API version: 1.0.0
-- Build date: 2019-05-27T15:39:26.158+08:00[Asia/Hong_Kong]
+- Build date: 2019-05-27T21:20:43.835+08:00[Asia/Hong_Kong]
 - Build package: org.openapitools.codegen.languages.DartJaguarClientCodegen
 
 ## Requirements

samples/client/petstore/dart-jaguar/flutter_proto_petstore/openapi/README.md

@@ -4,7 +4,7 @@ This is a sample server Petstore server. For this sample, you can use the api ke
 This Dart package is automatically generated by the [Open API Codegen](https://github.com/OpenAPITools/openapi-generator) project:
 
 - API version: 1.0.0
-- Build date: 2019-05-27T15:39:27.745+08:00[Asia/Hong_Kong]
+- Build date: 2019-05-27T21:20:45.456+08:00[Asia/Hong_Kong]
 - Build package: org.openapitools.codegen.languages.DartJaguarClientCodegen
 
 ## Requirements

samples/client/petstore/dart-jaguar/openapi/README.md

@@ -4,7 +4,7 @@ This is a sample server Petstore server. For this sample, you can use the api ke
 This Dart package is automatically generated by the [Open API Codegen](https://github.com/OpenAPITools/openapi-generator) project:
 
 - API version: 1.0.0
-- Build date: 2019-05-27T15:39:24.552+08:00[Asia/Hong_Kong]
+- Build date: 2019-05-27T21:20:42.193+08:00[Asia/Hong_Kong]
 - Build package: org.openapitools.codegen.languages.DartJaguarClientCodegen
 
 ## Requirements

samples/client/petstore/dart-jaguar/openapi/test/api_response_test.dart

@@ -3,7 +3,7 @@ import 'package:test/test.dart';
 
 // tests for ApiResponse
 void main() {
-  var instance = new Pet();
+  var instance = new ApiResponse();
 
   group('test ApiResponse', () {
     // int code (default value: null)

samples/client/petstore/dart-jaguar/openapi/test/category_test.dart

@@ -3,7 +3,7 @@ import 'package:test/test.dart';
 
 // tests for Category
 void main() {
-  var instance = new Pet();
+  var instance = new Category();
 
   group('test Category', () {
     // int id (default value: null)

samples/client/petstore/dart-jaguar/openapi/test/order_test.dart

@@ -3,7 +3,7 @@ import 'package:test/test.dart';
 
 // tests for Order
 void main() {
-  var instance = new Pet();
+  var instance = new Order();
 
   group('test Order', () {
     // int id (default value: null)

samples/client/petstore/dart-jaguar/openapi/test/tag_test.dart

@@ -3,7 +3,7 @@ import 'package:test/test.dart';
 
 // tests for Tag
 void main() {
-  var instance = new Pet();
+  var instance = new Tag();
 
   group('test Tag', () {
     // int id (default value: null)

samples/client/petstore/dart-jaguar/openapi/test/user_test.dart

@@ -3,7 +3,7 @@ import 'package:test/test.dart';
 
 // tests for User
 void main() {
-  var instance = new Pet();
+  var instance = new User();
 
   group('test User', () {
     // int id (default value: null)