remove unnecessary sys.path manipulation in tests

tests/document/__init__.py

@@ -1,5 +1,3 @@
-import sys
-sys.path[0:0] = [""]
 import unittest
 
 from class_methods import *

tests/document/class_methods.py

@@ -1,6 +1,4 @@
 # -*- coding: utf-8 -*-
-import sys
-sys.path[0:0] = [""]
 import unittest
 
 from mongoengine import *

tests/document/delta.py

@@ -1,6 +1,4 @@
 # -*- coding: utf-8 -*-
-import sys
-sys.path[0:0] = [""]
 import unittest
 
 from bson import SON

tests/document/dynamic.py

@@ -1,6 +1,4 @@
 import unittest
-import sys
-sys.path[0:0] = [""]
 
 from mongoengine import *
 from mongoengine.connection import get_db

tests/document/inheritance.py

@@ -1,6 +1,4 @@
 # -*- coding: utf-8 -*-
-import sys
-sys.path[0:0] = [""]
 import unittest
 import warnings
 

tests/document/json_serialisation.py

@@ -1,6 +1,3 @@
-import sys
-sys.path[0:0] = [""]
-
 import unittest
 import uuid
 

tests/document/validation.py

@@ -1,7 +1,4 @@
 # -*- coding: utf-8 -*-
-import sys
-sys.path[0:0] = [""]
-
 import unittest
 from datetime import datetime