clean up instance variable

make sure everything is passed to bootstrap or used correctly
if salt_host isn't specified, use ssh_host
Fix broken links in contributing documentation.
clean last pylint
add networks to nova driver
add private nics to nova
Merge pull request #15047 from gtmanfred/clean-salt-host

Clean salt host
Merge pull request #15048 from wackycaptain/fix-doc-contributing

Fix broken links in contributing documentation.
add a note about networks
utils: verify: simplified code
Now checks if the package name is valid

Currently fetches the entire package listing for each check. Next step
is to cache the packages for each session. I read about one of the
__var__'s that salt has that does caching like that.
Cache the package listing per run
Merge pull request #15052 from SaveTheRbtz/cosmetic_fixes

utils: verify: simplified code
Package removal is working
Added ability to update all installed packages

Cygwin does not appear to have a way to just upate individual packages.
Also probably not a good idea since it can all be pretty tightly
coupled.
Pep8'ified
Some more style fixes, swap before and after diff

Only functional change is to fix the order of the diff. It is correct
now.
Add file_tree external pillar (should fix #13510).
Merge pull request #15045 from veidt/develop

Include dependency required for debconfmod
Fixing #14778 - When mount is True we need to ensure the directory exists