anchor.diff:  
   # install pip packages
   RUN pip3 install boto3 sh argparse awscli
  +
  
positive.code: RUN unzip /root/workspace/packer_${PACKER_VERSION}_linux_amd64.zip -d /opt/packer/
  RUN ln -s /opt/packer/packer /usr/local/bin/packer
  
  # install ansible
  RUN pip3.6 install pip --upgrade
  RUN pip3 install ansible==${ANSIBLE_VERSION}
  
  # install terraform and create an symlink on /usr/local
  
negative.code: ARG ansible_version_arg=2.8.3
  ARG terraform_version_arg=0.12.24
  ARG terragrunt_version_arg=0.23.18
  ARG ami_manager_arg=0.8.0
  
  ENV PACKER_VERSION=${packer_version_arg}
  ENV ANSIBLE_VERSION=${ansible_version_arg}
  ENV TERRAFORM_VERSION=${terraform_version_arg}
  ENV TERRAGRUNT_VERSION=${terragrunt_version_arg}
  ENV AMI_MANAGER_VERSION=${ami_manager_arg}
  
  RUN yum update -y && \
      yum install -y wget && \
  