Add verify command.

releaser.conf

@@ -3,6 +3,7 @@ news_file: "NEWS"
 pypi: "dulwich"
 timeout_days: 5
 tag_name: "dulwich-$VERSION"
+verify_command: "make check"
 update_version {
   path: "setup.py"
   match: "^dulwich_version_string = '(.*)'$"