v0.5.4: docker: fix arg parsing for `build` found in args

Example: `docker run golang go build`

gnarly was detecting this as a `docker build` and injecting `buildx` so
the final command became: `docker run golang go buildx build`

Signed-off-by: Brian Goff <[email protected]>

v0.5.1: docker: Only generate sources list w/ config

Some cases we may not even have a config to load, so there is no reason
to generate the sources list since there will be nothing to replace.

v0.5.0

This release is cut solely to get a release done with the new go module name.