We were using v1.0.0 of Cobra as newer versions added spf13/viper as dependency,
which came with many indirect dependencies. Cobra v1.6.0 and up no longer depend
on viper, so we can now safely upgrade to the latest version.
full diff: https://github.com/spf13/cobra/compare/v1.0.0...v1.6.1
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Vndr has a simpler configuration and allows pointing to forked
packages. Additionally other docker projects are now using
vndr making vendoring in distribution more consistent.
Updates letsencrypt to use fork.
No longer uses sub-vendored packages.
Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
