Change default tags in DMARCReportInspectionFilter

Let's be consistent with existing filters like `ListMailsFilter`.
`ListMailsFilter` applies `lists` tag and `lists/<list-id>` tag.
`DMARCReportInspectionFilter` applies `dmarc` tag for each message
looking like DMARC report. To be consistent with lists, rather than
applying e.g. `dmarc-spf-ok` for SPF check passed, let's have
`dmarc/spf-ok` instead.

afew/filters/DMARCReportInspectionFilter.py

@@ -94,10 +94,10 @@ class DMARCReportInspectionFilter(Filter):
     '''
     def __init__(self,                     # pylint: disable=too-many-arguments
                  database,
-                 dkim_ok_tag='dmarc-dkim-ok',
-                 dkim_fail_tag='dmarc-dkim-fail',
-                 spf_ok_tag='dmarc-spf-ok',
-                 spf_fail_tag='dmarc-spf-fail'):
+                 dkim_ok_tag='dmarc/dkim-ok',
+                 dkim_fail_tag='dmarc/dkim-fail',
+                 spf_ok_tag='dmarc/spf-ok',
+                 spf_fail_tag='dmarc/spf-fail'):
         super(DMARCReportInspectionFilter, self).__init__(database)
         self.dkim_tag = {True: dkim_ok_tag, False: dkim_fail_tag}
         self.spf_tag = {True: spf_ok_tag, False: spf_fail_tag}