SeriesSalesImportServiceImpl.downloadAndParse(): add unit tests

[0pdd]

The puzzle 995-950efed9 from #995 has to be resolved:

mystamps/src/main/java/ru/mystamps/web/feature/series/importing/sale/SeriesSalesImportServiceImpl.java

Line 42 in bc3fe55

// @todo #995 SeriesSalesImportServiceImpl.downloadAndParse(): add unit tests

The puzzle was created by Slava Semushin on 03-Jun-19.

[php-coder]

Closed by 68030d2 commit.