Increase test timeout

We're seeing more random hard test timeouts -- who knows why?  Maybe
meltdown?  Maybe we just added more complicated tests and things
slowed down just a bit more.  Increase the timeout so we aren't as
affected.

Change-Id: I7b5b2465c3ec2ba7ca3472370a5a946ffb6293dd
diff --git a/tox.ini b/tox.ini
index 73915ad..e5035bd 100644
--- a/tox.ini
+++ b/tox.ini
@@ -6,7 +6,7 @@
 [testenv]
 basepython = python3
 setenv = VIRTUAL_ENV={envdir}
-         OS_TEST_TIMEOUT=120
+         OS_TEST_TIMEOUT=150
 passenv = ZUUL_TEST_ROOT OS_STDOUT_CAPTURE OS_STDERR_CAPTURE OS_LOG_CAPTURE OS_LOG_DEFAULTS
 usedevelop = True
 install_command = pip install {opts} {packages}