Use disco 0.5 for the travis builds.

.travis.yml

@@ -11,7 +11,7 @@ before_install:
   - sudo apt-get update -qq
   - sudo apt-get install -y curl erlang
   - git clone https://github.com/discoproject/disco.git /tmp/disco
-  - cd /tmp/disco && git checkout 0.4.5 && sudo make install
+  - cd /tmp/disco && git checkout 0.5 && sudo make install
   - cd lib && pip install .
   - popd