Remove thirdparty from tox.ini

Since the change Ib5e24e19bcba9808a9f49fe7f328668df77fe4f9 , the
directory thirdparty has been removed. So we don't need to specify
it on tox.ini anymore.

Change-Id: I7eddcb975ebf20a78920acd6f48ba8260f6cb75a
diff --git a/tox.ini b/tox.ini
index cff222d..111557f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -77,7 +77,7 @@
 # See the testrepository bug: https://bugs.launchpad.net/testrepository/+bug/1208610
 commands =
     find . -type f -name "*.pyc" -delete
-    bash tools/pretty_tox.sh '(?!.*\[.*\bslow\b.*\])(^tempest\.(api|scenario|thirdparty)) {posargs}'
+    bash tools/pretty_tox.sh '(?!.*\[.*\bslow\b.*\])(^tempest\.(api|scenario)) {posargs}'
 
 [testenv:full-serial]
 envdir = .tox/tempest
@@ -88,7 +88,7 @@
 # See the testrepository bug: https://bugs.launchpad.net/testrepository/+bug/1208610
 commands =
     find . -type f -name "*.pyc" -delete
-    bash tools/pretty_tox_serial.sh '(?!.*\[.*\bslow\b.*\])(^tempest\.(api|scenario|thirdparty)) {posargs}'
+    bash tools/pretty_tox_serial.sh '(?!.*\[.*\bslow\b.*\])(^tempest\.(api|scenario)) {posargs}'
 
 [testenv:smoke]
 envdir = .tox/tempest