Improve yaml_merge
Improve yaml_merge

Was unnecessarily complex. Was not merging items that were in
primary but not in secondary

tolbertam/ccm,josh-mckenzie/ccm,bcantoni/ccm,bcantoni/ccm,spodkowinski/ccm,pcmanus/ccm,pcmanus/ccm,AtwooTM/ccm,pcmanus/ccm,mike-tr-adamson/ccm,mikefero/ccm,pombredanne/ccm,mikefero/ccm,jeffjirsa/ccm,umitunal/ccm,mike-tr-adamson/ccm,slivne/ccm,tolbertam/ccm,jorgebay/ccm,mambocab/ccm,aboudreault/ccm,mike-tr-adamson/ccm,thobbs/ccm,kishkaru/ccm,thobbs/ccm,unusedPhD/ccm