(QENG-989,990) Clean up open source install rough edges

This ensures that puppet and friends are available after gem installs on
Solaris and Debian. It also makes sure that the config directory and
hiera.yaml file are aways present. The former change fixes QENG-989 while
the latter fixes QENG-990).
nit: please make this a multi-line `if` statement to match the rest in this method.