Added h2 as a dependency to wptserve/setup.py so that it can be built properly (#12472)

diff --git a/tools/wptserve/setup.py b/tools/wptserve/setup.py
index 194c337..c9c364b 100644
--- a/tools/wptserve/setup.py
+++ b/tools/wptserve/setup.py
@@ -1,7 +1,7 @@
 from setuptools import setup
 
 PACKAGE_VERSION = '2.0'
-deps = ["six>=1.8"]
+deps = ["six>=1.8", "h2==3.0.1"]
 
 setup(name='wptserve',
       version=PACKAGE_VERSION,