Add --update option to deploy create

To allow updating an existing deployment

- Check the deployment dir exists when updating
- Write to temp dir, then safely copy tree
- Don't overwrite data dir or config.env

tests/database/run-test.sh

@@ -86,7 +86,7 @@ fi
 echo "deploy init test: passed"
 
 # Switch to a full path for the data dir so it gets provisioned as a host bind mounted volume and preserved beyond cluster lifetime
-sed -i "s|^\(\s*db-data:$\)$|\1 ${test_deployment_dir}/data/db-data|" $test_deployment_spec
+sed -i.bak "s|^\(\s*db-data:$\)$|\1 ${test_deployment_dir}/data/db-data|" $test_deployment_spec
 
 $TEST_TARGET_SO --stack ${stack} deploy create --spec-file $test_deployment_spec --deployment-dir $test_deployment_dir
 # Check the deployment dir exists