Fix tests for load_dotenv with new verbose option

Author: maxkoryukov

tests/test_core.py

@@ -10,7 +10,7 @@
 
 def test_warns_if_file_does_not_exist():
     with warnings.catch_warnings(record=True) as w:
-        load_dotenv('.does_not_exist')
+        load_dotenv('.does_not_exist', verbose=True)
 
         assert len(w) == 1
         assert w[0].category is UserWarning