travis: add python-twisted
diff --git a/build/travis/installDependencies.sh b/build/travis/installDependencies.sh
index 852a805..dd92568 100755
--- a/build/travis/installDependencies.sh
+++ b/build/travis/installDependencies.sh
@@ -30,7 +30,7 @@
 sudo update-java-alternatives -s java-1.7.0-openjdk-amd64
 
 # Python dependencies
-sudo apt-get install -qq python-all python-all-dev python-all-dbg python-setuptools python-support
+sudo apt-get install -qq python-all python-all-dev python-all-dbg python-setuptools python-support python-twisted
 
 # Ruby dependencies
 sudo apt-get install -qq ruby ruby-dev