Added kubectl.

Dockerfile

@@ -3,10 +3,12 @@ RUN apk add --update --no-cache git build-base
 RUN go get github.com/awslabs/amazon-ecr-credential-helper/ecr-login/cli/docker-credential-ecr-login
 RUN wget https://s3.amazonaws.com/amazon-ecs-cli/ecs-cli-linux-amd64-latest && \
     install -m755 ecs-cli-linux-amd64-latest /usr/local/bin/ecs-cli
+RUN wget https://storage.googleapis.com/kubernetes-release/release/$(wget -O - https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/linux/amd64/kubectl && \
+    install -m755 kubectl /usr/local/bin/
 
 FROM docker:latest
 
 FROM python:3.7-alpine3.7
 COPY --from=docker /usr/local/bin/docker /usr/local/bin/
-COPY --from=ecs /go/bin/docker-credential-ecr-login /usr/local/bin/ecs-cli /usr/local/bin/
+COPY --from=ecs /go/bin/docker-credential-ecr-login /usr/local/bin/ecs-cli /usr/local/bin/kubectl /usr/local/bin/
 RUN pip install --no-cache-dir --progress-bar=off awscli docker-compose