fix caddy Dockerfile from previous commit.

caddy/Dockerfile

@@ -2,7 +2,9 @@ FROM alpine:3.4
 
 MAINTAINER Eric Pfeiffer <computerfr33k@users.noreply.github.com>
 
-LABEL caddy_version="0.9.1" architecture="amd64"
+ENV caddy_version=0.9.1
+
+LABEL caddy_version="$caddy_version" architecture="amd64"
 
 RUN apk update \
     && apk upgrade \
@@ -10,14 +12,13 @@ RUN apk update \
 
 RUN curl --silent --show-error --fail --location \
       --header "Accept: application/tar+gzip, application/x-gzip, application/octet-stream" -o - \
-      "https://github.com/mholt/caddy/releases/download/v0.9.1/caddy_linux_amd64.tar.gz" \
+      "https://github.com/mholt/caddy/releases/download/v$caddy_version/caddy_linux_amd64.tar.gz" \
     | tar --no-same-owner -C /usr/bin/ -xz caddy_linux_amd64 \
  && mv /usr/bin/caddy_linux_amd64 /usr/bin/caddy \
- && chmod 0755 /usr/bin/caddy \
- && /usr/bin/caddy -version
+ && chmod 0755 /usr/bin/caddy
 
 EXPOSE 80 443 2015
 
 WORKDIR /var/www/laravel/public
 
-CMD ["caddy" "-conf", "/etc/Caddyfile"]
+CMD ["/usr/bin/caddy", "-conf", "/etc/Caddyfile"]