Pass extra args to custom create command (#972)

This is needed to allow custom deploy commands to handle arbitrary args.

* Adds a `DeploymentContext.modify_yaml` helper
* Removes `laconicd` from test stack to simplify it

Reviewed-on: cerc-io/stack-orchestrator#972
Reviewed-by: ashwin <ashwin@noreply.git.vdb.to>

tests/deploy/run-deploy-test.sh

@@ -14,8 +14,13 @@ delete_cluster_exit () {
 
 # Test basic stack-orchestrator deploy
 echo "Running stack-orchestrator deploy test"
-# Bit of a hack, test the most recent package
-TEST_TARGET_SO=$( ls -t1 ./package/laconic-so* | head -1 )
+
+if [ "$1" == "from-path" ]; then
+    TEST_TARGET_SO="laconic-so"
+else
+    TEST_TARGET_SO=$( ls -t1 ./package/laconic-so* | head -1 )
+fi
+
 # Set a non-default repo dir
 export CERC_REPO_BASE_DIR=~/stack-orchestrator-test/repo-base-dir
 echo "Testing this package: $TEST_TARGET_SO"