setup.cfg: also accept css_inline < 0.14

No breakage observed when using newer versions like 0.13

setup.cfg

@@ -60,7 +60,7 @@ testing =
 	lxml
         pytest
 css_inlining =
-	css_inline >= 0.11, < 0.12        # >= 0.11, < 0.12: CSSInliner(inline_style_tags=..., keep_link_tags=..., keep_style_tags=...)
+	css_inline >= 0.11, < 0.14        # >= 0.11, < 0.14: CSSInliner(inline_style_tags=..., keep_link_tags=..., keep_style_tags=...)
 
 
 [options.entry_points]