Add functest return status in Alpines

Add functest return status in Alpines

So far we had 2 approaches:

 * return Functest CI status: can be OK even if tests are FAIL
 * return Functest Test status: can be FAIL even if all Functest tests are OK
 (Fail in onboaraded tests)

A 3rd way is possible thanks to [1].
We consider only Functest status and Functest tests for the return statement

the return will be FAIL only if

 * error in the framework
 * error in Functest Tests

So concretely, if promise, Doctor can be FAIL, if Functest tests are OK, the
return will be PASS

[1]: https://gerrit.opnfv.org/gerrit/#/c/42245/

Change-Id: I6c7fbe99d888e43700ddb2dfc9bfd6cc9bfbaed6
Signed-off-by: Morgan Richomme <morgan.richomme@orange.com>