Bump cobra to 1.3.0, replace completion command

[svix-frank]

The new version of cobra autogenerates a completion command which has the same interface as our custom one, so we can update and drop our command (fewer things to support)! 🎉

[tasn]

🎉

[fcjr]

This might be minor but I realized the short desc for the generated command starts with a lowercase letter which looks pretty unprofessional given the rest are capitalized. (The help desc is autogenerated with an uppercase so we can't just change to all lowercase). I made a PR to upstream, gonna hold off on merging this until its released. spf13/cobra#1455

[svix-frank]

This might be minor but I realized the short desc for the generated command starts with a lowercase letter which looks pretty unprofessional given the rest are capitalized. (The help desc is autogenerated with an uppercase so we can't just change to all lowercase). I made a PR to upstream, gonna hold off on merging this until its released. spf13/cobra#1455

My cobra patch finally got merged, just waiting for them to make another release.

[tasn]

🎉