Myiac failed when terraform init needed

[bartlomiejsawicki]

Myiac is not running init when terraform required it. For example when changes in terraform version are made myiac should run terraform init

Steps to reproduce the behavior:

1. Build env with terraform 0.12
2. Upgrade terraform in dev image to 0.15
3. Run destroy or create cluster
4. Myiac exit with error that terraform init is required

Myiac should detect message about missing terraform init and run it or at least has option to do it manually.