update existing packages by default

If a user already has a package installed it's highly unlikely they want
to create a new one from scratch.  This also removes the --name switch
as it no longer serves a useful purpose.

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
reorder switch usage information

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
bump version -> 2.0

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
add output files to .gitignore

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>