tests: add support for worker awareness

VppTestCase now has vpp_worker_count property set to number of workers.
This can be overriden by child classes. Also overriden by
VPP_WORKER_CONFIG variable for legacy reasons.

Type: improvement
Change-Id: Ic328bacb9003ddf9e92815767653bd362aa7f086
Signed-off-by: Klement Sekera <ksekera@cisco.com>
diff --git a/src/plugins/quic/test/test_quic.py b/src/plugins/quic/test/test_quic.py
index d984b99..0e4cb2d 100644
--- a/src/plugins/quic/test/test_quic.py
+++ b/src/plugins/quic/test/test_quic.py
@@ -177,7 +177,7 @@
     post_test_sleep = 1
     app = "vpp_echo"
     evt_q_len = 16384
-    worker_config = "workers 1"
+    vpp_worker_count = 1
     server_fifo_size = "1M"
     client_fifo_size = "4M"
     extra_vpp_punt_config = ["session", "{",