VOL-1060: Test Case: DHCP

Delivery of DHCP Test Case

Add missing Firewall call in Robot
Calling dhclient directly and not via bash
Therefore Lib fix is unnecessary
Logging to file dhcp assignment response
Other minor changes in Robot
Common Retry Timeout and Interval in "Wait Until Keyword Succeeds" moved to variables
Removed DHCP deactivate from Test Case

Change-Id: If9902e2b3606ac14af2c2f8ece34db074b373c50
diff --git a/tests/atests/common/auto_test.py b/tests/atests/common/auto_test.py
index f4b90ae..b43665a 100755
--- a/tests/atests/common/auto_test.py
+++ b/tests/atests/common/auto_test.py
@@ -26,6 +26,7 @@
 import preprovisioning
 import discovery
 import authentication
+import dhcp
 import logging
 
 DEFAULT_LOG_DIR = '/tmp/voltha_test_results'
@@ -79,4 +80,6 @@
 
     authentication.run_test(ROOT_DIR, VOLTHA_DIR, LOG_DIR)
 
+    dhcp.run_test(ROOT_DIR, VOLTHA_DIR, LOG_DIR)
+
     time.sleep(5)