Ignore all warnings from markdown module

Unfortunately newest versions are issuing further warnings; we need
to ignore those until at least we upgrade errobot (#16) to see if the
warnings go away

pytest.ini

@@ -1,6 +1,6 @@
 [pytest]
 filterwarnings=
     error
-    ignore:::markdown
+    ignore:::markdown.*
     ignore:invalid escape sequence::bottle
-    ignore:Using or importing the ABCs::bottle|jinja2
+    ignore:Using or importing the ABCs::bottle|jinja2