Improvements for Dockerfile; docker-compose file added

Dockerfile

@@ -0,0 +1,25 @@
+# First build step
+FROM golang:1.9-alpine as builder
+
+WORKDIR /go/src/cowyo
+COPY . .
+# Disable crosscompiling
+ENV CGO_ENABLED=0
+
+# Install git and make, compile and cleanup
+RUN apk add --no-cache git make \
+	&& go get -u github.com/schollz/cowyo \
+    && go get -u github.com/jteeuwen/go-bindata/... \
+    && make \
+    && apk del --purge git make \
+    && rm -rf /var/cache/apk*
+
+# Second build step uses the minimal scratch Docker image
+FROM scratch
+# Copy the binary from the first step
+COPY --from=builder /go/src/cowyo/cowyo /usr/local/bin/cowyo
+# Expose data folder
+VOLUME /data
+EXPOSE 8050
+# Start cowyo listening on any host
+CMD ["cowyo", "--host", "0.0.0.0"]