bitbake: toaster: tests Add a BuildTest helper class

Add a helper class for running build tests. Subclass this and call the
build method to get setup for running tests on the resulting data from a
build.

(Bitbake rev: 2cafb16033b2f38156e6e0a74c02120f87a4fa92)

Signed-off-by: Michael Wood <michael.g.wood@intel.com>
Signed-off-by: Elliot Smith <elliot.smith@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/toaster/tests/builds/README

@@ -6,7 +6,7 @@ Your oe build environment must be sourced/initialised for these tests to run.
 The simplest way to run the tests are the following commands:
 
 $ . oe-init-build-env
-$ cd lib/toaster/ # path my vary but this is into toaster's directory
+$ cd bitbake/lib/toaster/ # path my vary but this is into toaster's directory
 $ DJANGO_SETTINGS_MODULE='toastermain.settings-test' ./manage.py test tests.builds
 
 Optional environment variables: