Added apt-get cache cleanup
FROM golang:1.13
-RUN apt-get update ; apt-get install -y docker.io
+RUN apt-get update && apt-get install -y docker.io \
+ && rm -rf /var/lib/apt/lists/*
RUN go get -u github.com/onsi/ginkgo/ginkgo # installs the ginkgo CLI
RUN go get -u github.com/onsi/gomega/... # fetches the matcher library
