add fully static linked build target to makefile and refactor Dockerfile and docker-compose.yml

[Yigong Liu]

. add build-static target to Makefile to build fully static linked binary.
. refactor Dockerfile, since using build-static, we don't need alpine/muslc toolchain which IMHO mostly solve cgo/glibc dependence. For multistage dockerfile, use standard golang image for first build stage and "scratch" or "busybox" as base for final deploy which results an image half size of original alpine based image.
. refactor docker-compose.yml with more consistent image names.

[Travis Jeffery]

I'm gonna leave it for now, we can optimize later. We're already using alpine and the builder pattern so it's not like the images that big.