Fix coverage

Author: fantix

.coveragerc

@@ -12,3 +12,4 @@ exclude_lines =
     def __repr__
     raise NotImplementedError
     except ImportError
+    if gino.__version__ >= '0.8.0':

tests/test_loader.py

@@ -240,7 +240,7 @@ async def test_tuple_loader_279(user):
             assert len(row) == 2
 
 
-async def test_281_none_as_none(user):
+async def test_none_as_none_281(user):
     import gino
 
     if gino.__version__ < '0.9':