Store artifacts from the remote Jenkins slave if present

- collect artifacts from the remote Jenkins slave
  if $jenkins_slave_node_name != ${NODE_NAME}

- store py.test logs into files with different names to
  avoid overwrites

Change-Id: I1ba4fe425c5400f9095e5cd8b7e3d901be01d288
diff --git a/jobs/pipelines/swarm-run-pytest.groovy b/jobs/pipelines/swarm-run-pytest.groovy
index 1e4c849..d403861 100644
--- a/jobs/pipelines/swarm-run-pytest.groovy
+++ b/jobs/pipelines/swarm-run-pytest.groovy
@@ -73,6 +73,7 @@
                     export SALT_USER=\$SALTAPI_USER
                     export SALT_PASSWORD=\$SALTAPI_PASS
 
+                    export LOG_NAME=swarm_run_pytest.log
                     py.test --junit-xml=nosetests.xml ${RUN_TEST_OPTS}
 
                     """)