add check for public suffix

.travis.yml

@@ -0,0 +1,6 @@
+language: python
+python:
+  - "3.6"
+script:
+  - python verify.py
+

requirements.txt

@@ -0,0 +1 @@
+publicsuffixlist

verify.py

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+#!/usr/bin/env python
+
+"""Verify the integrity of the domain blacklist
+"""
+
+import sys
+
+from publicsuffixlist import PublicSuffixList
+
+def main(arguments):
+    psl = PublicSuffixList()
+    with open("disposable_email_blacklist", "r") as deb:
+        for line in deb:
+            if psl.publicsuffix(line) != line:
+                print(f'The following line is a public suffix: {line} - please remove it from the blacklist file. See https://publicsuffix.org for details.')
+
+
+if __name__ == "__main__":
+    main(sys.argv)