PUP-3255 improve acceptance pre suite

fix git install options
fix redhat json install issues
fix git url#branch generation

helps get machines up quickly when manual testing or writing tests.
might impact CI?
is it a problem to have it try to install in both places? i use acceptance setup to bring up machines all day everyday.  i don't want to remember when and if i have to use --add-el-extras.  what's the best way here? @rji