BuildRunConfig constructs the our primary RunConfig object using the given AWS session and the CLI args from viper.

Execute adds all child commands to the root command and sets flags appropriately.

NewEcsClient creates a new ecsClient for the given RunConfig.

InitCmd is responsible for creating a `ecsrun.yml`.

RunConfig is the main config object used to configure the RunTask.

VersionInfo is used by the `--version` command to output version info.

ECSClient is the wrapper around the aws-sdk ECS client and its various structs / methods.