In fact, there is a problem with the install-template command. In Grails version 3.1 it doesn't create the artifact directory with the views pages (gsp) as expected.
You just have to create an artifact directory and put your customized view pages in it:
/$YOUR_GRAIL_APP_DIR/src/main/templates/artifacts/scaffolding/create.gsp
/$YOUR_GRAIL_APP_DIR/src/main/templates/artifacts/scaffolding/edit.gsp
/$YOUR_GRAIL_APP_DIR/src/main/templates/artifacts/scaffolding/index.gsp
/$YOUR_GRAIL_APP_DIR/src/main/templates/artifacts/scaffolding/show.gsp
Regards,
-- Sylvio