On Debian installations, wget is installed even into the most minimal
environment. Even Python support on Debian cannot be guaranteed if
Standard System Utilities was not selected at installation time (or if
debootstrap was used), which is why the retrieved bootstrap-salt.sh
script takes care of installing it prior to installing Salt.
Prior to this commit, because of how the bootstrap salt shell file
worked, if github could not be resolved, the installer script would fail
silently with an exit code 0 because `sh` would evalute without any
errors and the curl exit code would be ignored. This commit splits out
the installer to first attempt to save the bash installer, and if it
exists, execute it.
Adam Bolte
Brian Cain
Mitchell Hashimoto
Daniel Miller
Ray Elsleiman
Raadad Elsleiman