TimedSiteParser: add unit tests

[0pdd]

The puzzle 801-b1837c29 from #801 has to be resolved:

mystamps/src/main/java/ru/mystamps/web/util/extractor/TimedSiteParser.java

Line 27 in 0dac42b

// @todo #801 TimedSiteParser: add unit tests

The puzzle was created by Slava Semushin on 02-Jan-18.

[php-coder]

Perhaps we can wait until #804 will be fixed (it should reduce number of methods in the interface).