Revert "add Dockerfile"

This reverts commit c0a6a4c045.

Dockerfile

@@ -1,22 +0,0 @@
-FROM golang:1.14.5 AS build-env
-
-LABEL maintainer="Max Schmitt <max@schmitt.mx>"
-LABEL maintainer="Andreas Schmid <service@aaschid.de>"
-LABEL description="FRITZ!Box Prometheus exporter"
-
-RUN go get -v github.com/aaschmid/fritzbox_exporter && \
-    cd /go/src/github.com/aaschmid/fritzbox_exporter && \
-    CGO_ENABLED=0 go build -v -o /exporter
-
-
-FROM alpine
-
-RUN apk update && apk add ca-certificates
-
-COPY --from=build-env /go/src/github.com/aaschmid/fritzbox_exporter/metrics.json /metrics.json
-COPY --from=build-env /exporter /
-
-EXPOSE 9133
-
-ENTRYPOINT ["/exporter"]
-CMD ["-listen-address", ":9133", "-metrics-file", "/metrics.json"]