Add terraform to docker image

Dockerfile

@@ -3,8 +3,12 @@ FROM python:3.8-slim
 ENV S3CMD_VER=2.3.0
 ENV ANSIBLE_VER=4.10.0
 ENV OSC_VER=5.8.0
+ENV TF_VER=1.4.6
 
 ADD ./packer /usr/local/bin
+RUN wget https://releases.hashicorp.com/terraform/${TF_VER}/terraform_${TF_VER}_linux_amd64.zip \
+    && unzip terraform_${TF_VER}_linux_amd64.zip \
+    && rm terraform_${TF_VER}_linux_amd64.zip
 RUN apt-get update && apt-get install --no-install-recommends -y \
     git \
     ssh \