Write registry creds to a file and remove helm2 functionality

Changelog for 0.6.11:

• PR #208 remove duplicated code for downloading helm by @amalkh5
• PR #204 Remove helm 2 by @amalkh5

Commits
b7c1dd6 Write registry creds to a file by @alexellis
edf2f25 Update README for newer apps / CLIs by @alexellis
3c749d8 remove duplicated code for downloading helm by @amalkh5
5ba2ecd remove helm2 by @amalkh5
bca66b0 Add set flag to ingress-nginx by @alexellis

Generated by Derek