binary files are not detected properly

See #62, release log:

• a8912ac by @yegor256: #62 polish
• f0d0147 by @yegor256: #62 binary detection works
• 12a4495 by @yegor256: #62 ptools removed
• 3e4a56b by @yegor256: #62 bug
• 953a223 by @yegor256: #62 test enabled

Released by Rultor 1.62.3, see build log