Automatically create mailing lists for registrars

This improves one of our gTech processes so they no longer have to remember to create Google Groups for a registrar after creating that registrar.

The ConfirmingCommand.verify() method is renamed to be more general purpose, so that it can do anything that follows naturally after a successful execution, such as creating Google Groups groups.

Minor refactoring is done around RegistryToolEnvironment handling for tests to make it more bullet-proof and general case.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117494277

java/com/google/domain/registry/tools/SetupOteCommand.java

@@ -117,6 +117,7 @@ final class SetupOteCommand extends ConfirmingCommand implements RemoteApiComman
   private void createRegistrar(String registrarName, String password, String tld) throws Exception {
     CreateRegistrarCommand command = new CreateRegistrarCommand();
     command.mainParameters = ImmutableList.of(registrarName);
+    command.createGoogleGroups = false; // Don't create Google Groups for OT&E registrars.
     command.allowedTlds = ImmutableList.of(tld);
     command.registrarName = registrarName;
     command.registrarType = Registrar.Type.OTE;