Fix a few Java 9+isms and ignore IML files (#973)

This allows us to run tests in IDEA which is significantly quicker. We
shouldn't be using anything past Java 8 anyway since that's what GAE
runs with.

.gitignore

@@ -75,7 +75,7 @@ local.properties
 autogenerated/
 
 # IDEA
-nomulus.iml
+**/*.iml
 nomulus.ipr
 nomulus.iws
 

core/src/main/java/google/registry/backup/ReplayCommitLogsToSqlAction.java

@@ -140,11 +140,13 @@ public class ReplayCommitLogsToSqlAction implements Runnable {
     transaction.stream()
         .sorted(ReplayCommitLogsToSqlAction::compareByWeight)
         .forEach(
-            versionedEntity ->
-                versionedEntity
-                    .getEntity()
-                    .ifPresentOrElse(
-                        this::handleEntityPut, () -> handleEntityDelete(versionedEntity)));
+            versionedEntity -> {
+              if (versionedEntity.getEntity().isPresent()) {
+                handleEntityPut(versionedEntity.getEntity().get());
+              } else {
+                handleEntityDelete(versionedEntity);
+              }
+            });
   }
 
   private void handleEntityPut(Entity entity) {

core/src/main/java/google/registry/tools/javascrap/BackfillRegistryLocksCommand.java

@@ -151,7 +151,7 @@ public class BackfillRegistryLocksCommand extends ConfirmingCommand
     return domains.stream()
         .filter(d -> d.getDeletionTime().isAfter(now))
         .filter(d -> d.getStatusValues().containsAll(REGISTRY_LOCK_STATUSES))
-        .filter(d -> RegistryLockDao.getMostRecentByRepoId(d.getRepoId()).isEmpty())
+        .filter(d -> !RegistryLockDao.getMostRecentByRepoId(d.getRepoId()).isPresent())
         .collect(toImmutableList());
   }
 }

core/src/test/java/google/registry/model/ImmutableObjectSubject.java

@@ -36,7 +36,6 @@ import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
-import java.util.function.Predicate;
 import java.util.stream.Collector;
 import javax.annotation.Nullable;
 
@@ -244,7 +243,7 @@ public final class ImmutableObjectSubject extends Subject {
 
       // We just need to check if there were any objects in "actual" that were not in "expected"
       // (where "found" is a proxy for "expected").
-    } else if (actual.stream().anyMatch(Predicate.not(found::contains))) {
+    } else if (!found.containsAll(actual)) {
       return ComparisonResult.createFailure();
     }