docker dev block update

The dev Dockerfile now works without superfluous go get calls.
At this point the -u option is really not what we want.
Merge pull request #436 from tstorch/docker-update

docker dev block update
Use variables, when the're there

Why not use the environment variables, when they are there...
Merge pull request #437 from tstorch/docker-update

Use variables, when the're there
add rel attribute such that font-awesome icons load correctly
Merge pull request #440 from deringer/dev

Correct loading of font-awesome styles from CDN