duplicates must be ignored during fixing

See #79, release log:

• 4716e20 by @yegor256: rultor up
• 7187184 by @yegor256: #79 test
• a3cfc0c by @yegor256: #79 test
• fb5f2be by @yegor256: #79 duplicates ignored
• e61a336 by @yegor256: #78 fixed
• 82bf451 by @yegor256: #77 fixed
• d6b305e by @yegor256: #77 rename
• 1bb5b95 by @yegor256: #76 check org too
• b962f71 by @yegor256: #76 more
• 889c166 by @yegor256: #76 swap
• 3f1e8fd by @yegor256: allow month
• a091ac7 by @yegor256: #75 IEEE/ACM removed
• 1e59137 by @yegor256: #74 IEEE simplified
• 7d14050 by @yegor256: #74 ACM simplified
• f53392d by @yegor256: #41 auto fix
• 40b9875 by @yegor256: #45 fixed
• f4e4f98 by @yegor256: #73 introduce howpublished
• afec75b by @yegor256: #67 allow month
• 3ac89ce by @yegor256: #72 allow howpublished and not
• ee50bf2 by @yegor256: #72 more tests
• and 6 more...

Released by Rultor 2.0-SNAPSHOT, see build log