Fix issue where plugin can resolve its promise before the gzip stream is done writing
Fix issue where plugin can resolve its promise before the gzip stream is done writing

ember-cli-deploy/ember-cli-deploy-gzip,achambers/ember-cli-deploy-gzip,lukemelia/ember-cli-deploy-gzip,lukemelia/ember-cli-deploy-gzip,achambers/ember-cli-deploy-gzip