more integration test debug tools

printBuild: Print the colored logs if the step has failed
tearDown: Print all builds if the test is failing

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
put the build dump as an error instead of print

This way the dump is useful in the console, and in the metabuildbot
Merge pull request #1473 from tardyp/integration2

more integration test debug tools