Use constants for import request statuses

[php-coder]

mystamps/src/test/java/ru/mystamps/web/tests/Random.java

Lines 37 to 45 in 29f6dc9

	// TODO: use constants for statuses
	private static final String[] STATUSES = new String[] {
	"Unprocessed",
	"DownloadingSucceeded",
	"DownloadingFailed",
	"ParsingSucceeded",
	"ParsingFailed",
	"ImportSucceeded",
	};

Tech debt for 29f6dc9 (#660)

[php-coder]

Maybe we even should use enum for them.