Many Many Fixes

[nmccready]

I don't really know where to begin on this as many dependencies and build processes were broken internally.

Off the top of my head some of the main problems:

• go is installed from official go downloads and prebuilt binaries (hg removed)

• go-bindata (archived and inactive / broken) moved to go-bindata/go-bindata from jteeuwen/go-bindata

• installation within the container was invalid with newer version of go where a src project should not be installed in $GOROOT. Instead cesium-terrain-server now gets installed in $GOPATH -> /root/go/...

• Removed versioning files which tracked cesium version and branch version. These were too static and easy to mess up. Instead these things are looked up by git within the Makefile

• go modules used to have better dependency integrity

• removed many unnecessary exit 1 by adding

  #!/usr/bin/env bash
  set -e
  set -o pipefail

[joshserrin]

Our project is running into this issue. Anyway this MR can get merged and new container published?