Build Docker image from current directory

I have a rather large project directory due to lots of build products, which means all of those are copied into the temporary directory by copyApplicationToTempLocation(). At first glance it appears this only exists such that it excludes .git and node_modules directories by default. There's a TODO in there for this to be more language independent, so I think the best path forward is to encourage users to create their own .dockerignore file, perhaps suggesting to generate one by default if one does not yet exist.

The Dockerfile built from the template could be put into a temp file since Docker supports specifying alternative files to build from.