anchor.diff:  
   # install shellcheck
   RUN set -ex && cd ~ \
  -  && curl -LO https://shellcheck.storage.googleapis.com/shellcheck-v0.6.0.linux.x86_64.tar.xz \
  +  && curl -sSLO https://shellcheck.storage.googleapis.com/shellcheck-v0.6.0.linux.x86_64.tar.xz \
     && [ $(sha256sum shellcheck-v0.6.0.linux.x86_64.tar.xz | cut -f1 -d' ') = 95c7d6e8320d285a9f026b5241f48f1c02d225a1b08908660e8b84e58e9c7dce ] \
     && tar xvfa shellcheck-v0.6.0.linux.x86_64.tar.xz \
     && sudo mv shellcheck-v0.6.0/shellcheck /usr/local/bin \
  
positive.code: 
  # install Go
  RUN set -ex && cd ~ \
    && curl -LO https://dl.google.com/go/go1.12.1.linux-amd64.tar.gz \
    && [ $(sha256sum go1.12.1.linux-amd64.tar.gz | cut -f1 -d' ') = 2a3fdabf665496a0db5f41ec6af7a9b15a49fbe71a85a50ca38b1f13a103aeec ] \
    && sudo tar -C /usr/local -xzf go1.12.1.linux-amd64.tar.gz \
    && sudo ln -s /usr/local/go/bin/* /usr/local/bin \
  
negative.code: 
  # install dep
  RUN set -ex && cd ~ \
    && curl -sSLO https://github.com/golang/dep/releases/download/v0.5.1/dep-linux-amd64 \
    && [ $(sha256sum dep-linux-amd64 | cut -f1 -d' ') = 7479cca72da0596bb3c23094d363ea32b7336daa5473fa785a2099be28ecd0e3 ] \
    && chmod 755 dep-linux-amd64 \
    && sudo mv dep-linux-amd64 /usr/local/bin/dep
  
  # install go-bindata
  RUN set -ex && cd ~ \
    && curl -sSLO https://github.com/kevinburke/go-bindata/releases/download/v3.11.0/go-bindata-linux-amd64 \
    && [ $(sha256sum go-bindata-linux-amd64 | cut -f1 -d' ') = fdebe82be2ea9db495c443d38e986cd438d97ec6719b2f69b35001d546da6e46 ] \
    && chmod 755 go-bindata-linux-amd64 \
    && sudo mv go-bindata-linux-amd64 /usr/local/bin/go-bindata
  
  # install Terraform
  RUN set -ex && cd ~ \
    && curl -sSLO https://releases.hashicorp.com/terraform/0.11.13/terraform_0.11.13_linux_amd64.zip \
    && [ $(sha256sum terraform_0.11.13_linux_amd64.zip | cut -f1 -d ' ') = 5925cd4d81e7d8f42a0054df2aafd66e2ab7408dbed2bd748f0022cfe592f8d2 ] \
    && sudo unzip -d /usr/local/bin terraform_0.11.13_linux_amd64.zip \
    && rm -f terraform_0.11.13_linux_amd64.zip
  
  # install terraform-docs
  RUN set -ex && cd ~ \
    && curl -sSLO https://github.com/segmentio/terraform-docs/releases/download/v0.6.0/terraform-docs-v0.6.0-linux-amd64 \
    && [ $(sha256sum terraform-docs-v0.6.0-linux-amd64 | cut -f1 -d' ') = 7863f13b4fa94f7a4cb1eac2751c427c5754ec0da7793f4a34ce5d5d477f7c4f ] \
    && chmod +x terraform-docs-v0.6.0-linux-amd64 \
    && sudo mv terraform-docs-v0.6.0-linux-amd64 /usr/local/bin/terraform-docs
  