tests: skip more excluded plugin tests

Check and skip VPP_EXCLUDED_PLUGINS tests for most of plugins.

Type: improvement
Signed-off-by: Dmitry Valter <d-valter@yandex-team.com>
Change-Id: I23fd3666729251c639aa8da72a676058e3f5bb4e

test/test_pnat.py

@@ -6,8 +6,10 @@ from scapy.layers.inet import Ether, IP, UDP, ICMP
 from framework import VppTestCase
 from asfframework import VppTestRunner
 from vpp_papi import VppEnum
+from config import config
 
 
+@unittest.skipIf("nat" in config.excluded_plugins, "Exclude NAT plugin tests")
 class TestPNAT(VppTestCase):
     """PNAT Test Case"""