avocado.core: Add a mapping of avocado error codes

Add a mapping of possible return codes for avocado,
to the meaning of them. We need to differentiate
simple jobs from tests failed, jobs that failed, and
avocado crashes.
Signed-off-by: NLucas Meneghel Rodrigues <lmr@redhat.com>

avocado/core/error_codes.py

+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+#
+# See LICENSE for more details.
+
+"""
+Maps the different avocado failure statuses to unix return codes.
+
+The current return codes are:
+    * AVOCADO_ALL_OK
+        Both job and tests PASSed
+    * AVOCADO_TESTS_FAIL
+        Job went fine, but some tests FAILed or ERRORed
+    * AVOCADO_JOB_FAIL
+        Something went wrong with the Job itself, by explicit
+        :class:`avocado.core.exceptions.JobError` exception.
+    * AVOCADO_CRASH
+        Something else went wrong and avocado plain crashed.
+"""
+
+numeric_status = {"AVOCADO_ALL_OK": 0,
+                  "AVOCADO_TESTS_FAIL": 1,
+                  "AVOCADO_JOB_FAIL": 2,
+                  "AVOCADO_CRASH": 3}

avocado/core/exceptions.py

@@ -16,7 +16,9 @@
 Exception classes, useful for tests, and other parts of the framework code.
 """
 
+
 class JobBaseException(Exception):
+
     """
     The parent of all job exceptions.
     """
@@ -24,6 +26,7 @@ class JobBaseException(Exception):
 
 
 class JobError(Exception):
+
     """
     A generic error happened during a job execution.
     """