remove utf8 encoding declaration in test files as it's not needed/recommended

tests/document/test_class_methods.py

@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import unittest
 
 from mongoengine import *

tests/document/test_delta.py

@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import unittest
 
 from bson import SON

tests/document/test_indexes.py

@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import unittest
 from datetime import datetime
 

tests/document/test_inheritance.py

@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import unittest
 import warnings
 

tests/document/test_instance.py

@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import os
 import pickle
 import unittest

tests/document/test_validation.py

@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 import unittest
 from datetime import datetime