* don't exit on no values provided but instead use sane defaults for
username, password and registry
* add "--no-push" flag if REPO name has not been specified
* only allow setting of TAGS if REPO has been specified as well
* rm arm/arm64/gcr/ecr related build instructions in build.sh
and .drone.ml, only build for amd64
* change autotag to manually specified tags (2 static, one dynamic)
* change the branch referenced in .drone.yml as we're using dev by
default
* module path is now git.dotya.ml/wanderer/drone-kaniko/*
