Refactor / simplify how Yaml schema Constraints work:

- simplify access to DynamicSchemaContext.
 - allow constraints on non-map type nodes.

These changes pave the way to checking inertaction constraint on job-name
used in 'passed' attribute.

concourse/set-pipeline.sh

@@ -1,3 +0,0 @@
-#!/bin/bash
-branch=`git rev-parse --abbrev-ref HEAD`
-fly -t tools set-pipeline --var "branch=${branch}" --load-vars-from ${HOME}/.sts4-concourse-credentials.yml -p sts4-${branch} -c pipeline.yml