Reverts docstring quoting syntax.
diff --git a/tests/test_varblock.py b/tests/test_varblock.py
index d6465ed..24ea50f 100644
--- a/tests/test_varblock.py
+++ b/tests/test_varblock.py
@@ -1,4 +1,4 @@
-"""Tests varblock operations."""
+'''Tests varblock operations.'''
 
 
 try: