WIP feat: allow cert-manager annotations on ingress based on environment variables PT.2

[cloud-j-luna]

This PR allows cert-manager annotations on ingress based on environment variables.

[cloud-j-luna]

Previously closed issue #86

[troian]

i'll summarize requests here so it would be easier to follow

• we use viper as interface to parse and prevalidate configuration parameter that can be defined using:
  • default values
  • config file
  • env variables
  • flags
• don't define env variables, but flags instead, each flag will have env variable automatically by Viper (refer to it's documentation if you are eager to know how it works). for example --home flag will have AKASH_HOME env variable bound to it.
• the configuration must be evaluated and validated within command handler and all subsequent instantiation must use go types corresponding to its values. think it this way: type safety is a top priority
• if value can take only two states then bool would be the correct type. for example
  instead

// sslEnable is a string type
if sslEnable != "" && sslEnable == "1" {

do

// sslEnable is a bool type
if sslEnable {

provider run would be a good place to start

[troian]

i marked it as WIP until all issues are resolved. feel free to remove when done

[ghost]

should it be yamlk?