Add import to filters.py

Add missing import to fix FilterByRegexpPath class

Author: stiwa-wrre

artifactory_cleanup/rules/filters.py

@@ -1,6 +1,6 @@
 from artifactory_cleanup.rules.utils import to_masks
 from artifactory_cleanup.rules.base import ArtifactsList, Rule
-
+import re
 
 class FilterRule(Rule):
     attribute_name = None