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/src/com/mirantis/system_qa/SharedPipeline.groovy b/src/com/mirantis/system_qa/SharedPipeline.groovy
index ed667b8..d74b600 100644
--- a/src/com/mirantis/system_qa/SharedPipeline.groovy
+++ b/src/com/mirantis/system_qa/SharedPipeline.groovy
@@ -541,6 +541,7 @@
     // Result will be stored in JUnit XML file deploy_${stack}.xml
     try {
         run_cmd("""\
+            export LOG_NAME=deploy_${stack}_test.log
             py.test --junit-xml=deploy_${stack}.xml -m check_${stack}
         """)
     } catch (e) {