Ensure Helm github org repo requirements are met

[scottrigby]

• Add code of conduct
• Ensure all past commits are signed (given there are only 12 commits and this repo was very recently added to the Helm github org unannounced, we agreed this is the easiest way to handle this requirement)
• Ensure correct licensing. Currently there's an MIT license and Apache licenses need to fix the copyright line.

[scottrigby]

@paulczar @unguiculus gave me go-ahead to sign their commits for them (just did git rebase -i --root and reworded all each commit to add the appropriate person's DCO signature).

For anyone else that may have cloned this repo – it hasn't had any release yet 🤷‍♂️go ahead and git reset --hard origin/master 😄

[scottrigby]

Reopening because we need to address licensing. Added to issue description.