Series import: add integration test for series condition

[0pdd]

The puzzle 1326-e5faca08 from #1326 has to be resolved:

mystamps/src/main/java/ru/mystamps/web/feature/series/importing/ImportSeriesSalesForm.java

Line 52 in 9153c9b

// @todo #1326 Series import: add integration test for series condition

The puzzle was created by Slava Semushin on 03-Jun-20.