Switch to alpine docker image, related to sosedoff#164

Dockerfile

@@ -1,12 +1,17 @@
-FROM golang:1.5
+FROM alpine:3.3
+MAINTAINER Dan Sosedoff <[email protected]>
 
-COPY . /go/src/github.com/sosedoff/pgweb
-WORKDIR /go/src/github.com/sosedoff/pgweb
+ENV PGWEB_VERSION 0.9.2
 
-RUN go get github.com/tools/godep
-
-RUN godep restore
-RUN godep go build && godep go install
+RUN \
+  apk update && \
+  apk add ca-certificates && \
+  update-ca-certificates && \
+  cd /tmp && \
+  wget https://github.com/sosedoff/pgweb/releases/download/v$PGWEB_VERSION/pgweb_linux_amd64.zip && \
+  unzip pgweb_linux_amd64.zip -d /usr/bin && \
+  mv /usr/bin/pgweb_linux_amd64 /usr/bin/pgweb && \
+  rm -f pgweb_linux_amd64.zip
 
 EXPOSE 8081
-CMD ["pgweb", "--bind", "0.0.0.0"]
+CMD ["/usr/bin/pgweb", "--bind=0.0.0.0", "--listen=8081"]