Update series: add integration test for non-empty "path" field

[0pdd]

The puzzle 785-140bc7bd from #785 has to be resolved:

mystamps/src/main/java/ru/mystamps/web/support/spring/mvc/PatchRequest.java

Line 42 in 7be4e62

// @todo #785 Update series: add integration test for non-empty "path" field

The puzzle was created by Slava Semushin on 24-May-20.