CollectionServiceImplTest: use single quotes.

Should be in a3f3704 commit.

No functional changes.

Author: php-coder

src/test/groovy/ru/mystamps/web/service/CollectionServiceImplTest.groovy

@@ -96,7 +96,7 @@ class CollectionServiceImplTest extends Specification {
 	@SuppressWarnings(['ClosureAsLastMethodParameter', 'FactoryMethodName', 'UnnecessaryReturnKeyword'])
 	def "createCollection() should assign updated at to current date"() {
 		when:
-			service.createCollection(123, "any-login")
+			service.createCollection(123, 'any-login')
 		then:
 			1 * collectionDao.add({ AddCollectionDbDto collection ->
 				assert DateUtils.roughlyEqual(collection?.updatedAt, new Date())