Add tests for image caching
Adjust tests and main app for cached builds
Remove obsolete command-line handling
Remove print statement from test
Fix subdirectory handling
Put back exception instead of sys.exit()
Argument parsing should only be used when calling from
the command line, and not be deeply tied into the class
itself. This makes it easier for folks to just set
traitlets on an empty class and start it, without having to
deal with passing arguments.
This breaks how people might already be using Repo2Docker as
a library, so should not be part of 0.7
Feels more natural to first attempt building the image and then running
the verify script in it.
Changed the name of the two tests to make it easier to see which test
failed (verify or build).