Remove unused methods.

These methods are not used outside of their tests and have no reason to
stick around anymore.
Add PATH searching for composer.
Add verbose logging.
Allow the app directory to use unstable versions.

For now we need to get unstable versions of app, at least until 3.0.0.
If the composer flag cannot be found look in $PATH.
Correct output message.
Merge pull request #3491 from markstory/3.0-project-bake-cleanup

3.0 project bake cleanup