Mostly Fix CI build

This mostly fixes the CI build, though an apparent problem with the actual script remains. There are 3 commits which I've chosen not to squash. They include these changes:

1. Eliminate wget installation in favor of previously installed curl.
2. Use environment variables in the way CI allows you to define them. Both ways work.
3. Use the --tool argument to mk-build-deps to avoid problems in the redirection of the yes command in a non-interactive terminal (any docker environment invoked without the -it arguments).
4. Add the --git-ignore-new flag to gbp to allow the command to progress.