*: prepare build scripts for a release

Dockerfile

@@ -1,11 +1,11 @@
-FROM alpine:latest
+FROM alpine:3.4
 
 MAINTAINER Eric Chiang <eric.chiang@coreos.com>
 
 RUN apk add --update ca-certificates 
 
-COPY bin/dex /dex
+COPY _output/bin/dex /usr/local/bin/dex
 
-ENTRYPOINT ["/dex"]
+ENTRYPOINT ["/usr/local/bin/dex"]
 
 CMD ["version"]