[test] stdnum 1.18+ is required, force it for tests

Change-Id: Id1cbcfbd5250e7c0f58c1e7f23511203123c5715
---
M tests/cosmetic_changes_tests.py
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/tests/cosmetic_changes_tests.py b/tests/cosmetic_changes_tests.py
index 9073fac..4c41716 100755
--- a/tests/cosmetic_changes_tests.py
+++ b/tests/cosmetic_changes_tests.py
@@ -562,7 +562,7 @@
     @classmethod
     def setUpClass(cls):
         """Skip tests if isbn libraries are missing."""
-        if not has_module('stdnum', version='1.17'):
+        if not has_module('stdnum', version='1.18'):
             raise unittest.SkipTest('python-stdnum is not available.')
         super().setUpClass()
 

