AIAP: support deploying manifests from patchsets

`airshipctl document pull` does not yet support pull from git refs,
and so cannot pull airshipctl patchsets to test their manifests.

As a workaround, this change copies the airshipctl project directory
that is used to build the binary / run the scripts
(which can be set to a patchset via $MANIFEST_REPO_REF) to the
expected /tmp location for serving manifests from patchsets as well.

Support for testing treasuremap manifest patchsets is still unsupported.

Change-Id: Ia9ec248efa2a12728e9eb6d3753b35ec5bae0d47

tools/airship-in-a-pod/runner/assets/entrypoint.sh

@@ -51,7 +51,10 @@ export AIRSHIP_CONFIG_MANIFEST_DIRECTORY="/tmp/airship"
 if [ "$MANIFEST_REPO_NAME" == "airshipctl" ]
 then
   ./tools/deployment/22_test_configs.sh
-  ./tools/deployment/23_pull_documents.sh
+  # `airshipctl document pull` doesn't support pull patchsets yet
+  #./tools/deployment/23_pull_documents.sh
+  mkdir /tmp/airship
+  cp -rp /opt/airshipctl /tmp/airship/airshipctl
   ./tools/deployment/23_generate_secrets.sh
 else
   ./tools/deployment/airship-core/22_test_configs.sh