Using environment variable within codeship command

codeship-services.yml

awsdeployment:
  image: alpine:3.5
  environment:
    - AWS_DEFAULT_REGION=us-east-1

codeship-steps.yml

- name: Deploy to S3
  service: awsdeployment
  command: sh -c "echo hello $AWS_DEFAULT_REGION"

output.log

jet steps
{StepStarted=step_name:"Deploy to S3"}
{ContainerRunStdout=step_name:"Deploy to S3" service_name:"awsdeployment"}: hello us-east-1
{StepFinished=step_name:"Deploy to S3" type:STEP_FINISHED_TYPE_SUCCESS}