Support Helm Diff

[osterman]

what

• Many flags break helm diff
  • --wait can be replaced with wait: true
  • --force is dangerous and shouldn't be used blindly
  • --reset-values is extraneous (roboll/helmfile#210 (comment))
  • --timeout also not supported and hopefully not generally needed

why

• The argument is only compatible with helm upgrade or helm install
• wait: true was recently released

references

• roboll/helmfile#222
• roboll/helmfile#230