move most of this image over to docker.jcg.re/base-caddy, to make it integratable

Dockerfile

@@ -1,43 +1,4 @@
-FROM docker.jcg.re/base-alpine
-MAINTAINER Jan Christian Grünhage <jan.christian@gruenhage.xyz>
-
-ARG CLONE_URL=github.com/mholt/caddy
-ARG BRANCH
-
-ENV GOPATH=/gopath \
-    UID=192 \
-    GID=192
-
-ADD plugins.txt /plugins
-
-RUN apk upgrade --update \
- && apk add \
-      build-base \
-      su-exec \
-      libcap \
-      go \
-      git \
-      bash \
- && mkdir -p ${GOPATH}/src/${CLONE_URL} \
- && cd $GOPATH/src/${CLONE_URL} \
- && git clone https://${CLONE_URL} . \
- && git checkout ${BRANCH:-$(git describe --abbrev=0 --tags)} \
- && cd caddy/caddymain \
- && export LINE="$(grep -n "// This is where other plugins get plugged in (imported)" < run.go | sed 's/^\([0-9]\+\):.*$/\1/')" \
- && head -n ${LINE} run.go > newrun.go \
- && cat /plugins >> newrun.go \
- && line=`expr ${LINE} + 1` \
- && tail -n +${LINE} run.go >> newrun.go \
- && rm -f run.go \
- && mv newrun.go run.go \
- && go get ${CLONE_URL}/... \
- && mv $GOPATH/bin/caddy /usr/bin \
- && setcap cap_net_bind_service=+ep /usr/bin/caddy \
- && apk del --purge build-base go \
- && mkdir /caddy \
- && rm -rf $GOPATH /var/cache/apk/* /plugins
-
+FROM docker.jcg.re/base-caddy
 ADD root /
-
 EXPOSE 2015 80 443
 VOLUME ["/caddy", "/var/www"]