dump output on failed build, remove by id not tag

v0.0.4

docker build: remove image by ID, not tag

Newest docker, .dockerignore support

Upgraded to newest (v19.03.4) version of Docker libs
Added support for .dockerignore for build contexts.

Custom Dockerfile name support

v0.0.2

Added Dockerfile to the build target

preview release

v0.0.1

added name option for the container