This change updates the fixtures files for the modules within
fuel-library to use the relative path to the upstream modules used by
fuel-library. With this change we are also adding an initial prep task
that is used by CI to pull down all the modules first and only one time
to reduce the amount of repeated calls to the upstream git repositories.
Included in this change is also an update to exclude all the upstream
modules from the spec and lint tasks as those are maintained in the
upstream modules and should not be done when testing fuel-library.
This change also adds documentation to the README.md on how to run the
tests from the root of fuel-library.
Change-Id: I9cde21b94a8367fd45cf046af48d7618076a385c
Related-Bug: #1535832
abd991b230