Memory leak because of missing `Drop` implementation.

See #79, release log:

• 93f5097 by @yegor256: #79 drop implemented
• 3b16b5d by @yegor256: Merge pull request #81 from ye...
• 9f1055a by @yegor256: new benchmark results
• afc339e by @yegor256: tag fix
• 55bd963 by @yegor256: Merge pull request #80 from ye...
• 352454e by @yegor256: new benchmark results
• 4fb2bb0 by @yegor256: #79 tests added
• 925f6a9 by @yegor256: Merge pull request #78 from ye...
• e83b890 by @yegor256: new benchmark results
• 38e24a6 by @yegor256: #69 more write instead of :=
• a47cb20 by @yegor256: #69 write instead of :=
• 7d24bde by @yegor256: cleaner script
• 9fd0c67 by @yegor256: Merge pull request #76 from ye...
• a62f2fc by @yegor256: new version in README
• 3a862b4 by @yegor256: no Copy
• 1b67747 by @yegor256: on tags

Released by Rultor 1.74.7, see build log