Prepare for docker-build 0.1.1 merge into master

Please see mate-desktop/mate-dev-scripts#13

.travis.yml

@@ -10,6 +10,9 @@ before_install:
   - chmod +x docker-build
 
 install:
+  - sudo apt-get install -y python3-pip python3-setuptools
+  - sudo pip3 install --upgrade pip
+  - sudo pip install PyGithub
   - ./docker-build --name ${DISTRO} --config .travis.yml --install
 
 script:
@@ -97,7 +100,6 @@ requires:
     - redhat-rpm-config
 
   ubuntu:
-    # Same as debian
     - git
     - libcanberra-gtk3-dev
     - libdbus-glib-1-dev