CORD-2524: Fix shift/reduce conflicts and general improvements to parser

Change-Id: I43ff148047b8d1286d52e6621ba17d76602b515e
diff --git a/containers/xos/pip_requirements.txt b/containers/xos/pip_requirements.txt
index 7222fa3..97ed749 100644
--- a/containers/xos/pip_requirements.txt
+++ b/containers/xos/pip_requirements.txt
@@ -168,4 +168,4 @@
 zope.interface==4.3.3
 redis==2.10.5
 astunparse==1.5.0
-plyxproto==2.2.0
+plyxproto==3.0.1