test(library): compare trend move times as Instants

Sort the parsed Instant values, not the raw strings. String order
is wrong when fraction lengths differ. Refs #45.

src/test/java/core_service/modules/library/api/StatGamesFlowTest.java

@@ -260,7 +260,8 @@ class StatGamesFlowTest extends AbstractMockedLibraryServicesTest {
         List<JsonNode> rows = allRows("TREND_MOVES", null);
 
         assertThat(rows).extracting(r -> r.get("appid").asLong()).contains(FINISHED_TRACKED, BACK_TO_PILE);
-        assertThat(rows).extracting(r -> r.get("at").asString()).isSortedAccordingTo(java.util.Comparator.reverseOrder());
+        assertThat(rows).extracting(r -> java.time.Instant.parse(r.get("at").asString()))
+                .isSortedAccordingTo(java.util.Comparator.reverseOrder());
         assertThat(rows).filteredOn(r -> r.get("appid").asLong() == BACK_TO_PILE)
                 .extracting(r -> r.get("fromStatus").asString(), r -> r.get("toStatus").asString())
                 .contains(org.assertj.core.groups.Tuple.tuple("PLAYING", "BACKLOG"));