Rename fixtures directory to job_fixtures to prepare for adding view_fixtures
directory in the following commits.
Change-Id: Ic20997cae020b542ddc22bf444fa6b92fbcae064
JJB currently allows for named defaults to be specified at both the
project and template level. Add a test case that exercises this and
demonstrates that current interpolation ignores variables without
definitions if they are not subsequently used when expanding the
template.
Change-Id: Iffdda9f79c12fb71077bf621f8b08381dbcc9ac1