Merge pull request #9339 from makdharma/dockerfile

dockerfile update for http2_badserver_interop

tools/dockerfile/interoptest/grpc_interop_http2/Dockerfile

@@ -46,6 +46,7 @@ RUN apt-get update && apt-get install -y \
 RUN pip install pip --upgrade
 RUN pip install virtualenv
 RUN pip install futures==2.2.0 enum34==1.0.4 protobuf==3.0.0a2 six==1.10.0
+RUN pip install twisted h2
 
 # Define the default command.
 CMD ["bash"]