Use a script so you can write something resembling real code and reason about how it works.

.travis.yml

@@ -26,15 +26,7 @@ env:
     - TOX_ENV=py3pep8
 
 install:
-    - "sudo add-apt-repository \"deb http://archive.ubuntu.com/ubuntu/ lucid main\""
-    - sudo add-apt-repository -y ppa:pypy/ppa
-    - sudo apt-get -y update
-    - "[[ ${OPENSSL} == \"0.9.8\" ]] && sudo apt-get -y --force-yes install libssl-dev/lucid"
-    - "[[ ${TOX_ENV} == pypy ]] && sudo apt-get -y install pypy"
-    # This is required because we need to get rid of the Travis installed PyPy
-    # or it'll take precedence over the PPA installed one.
-    - "[[ ${TOX_ENV} == pypy ]] && sudo rm -rf /usr/local/pypy/bin"
-    - pip install tox coveralls
+    - ./.travis/install.sh
 
 script:
     - tox -e $TOX_ENV

.travis/install.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+
+set -e
+set -x
+
+if [[ "${OPENSSL}" == "0.9.8" ]]; then
+    sudo add-apt-repository "deb http://archive.ubuntu.com/ubuntu/ lucid main"
+fi
+
+if [[ "${TOX_ENV}" == "pypy" ]]; then
+    sudo add-apt-repository -y ppa:pypy/ppa
+fi
+
+sudo apt-get -y update
+
+if [[ "${OPENSSL}" == "0.9.8" ]]; then
+    sudo apt-get install -y --force-yes libssl-dev/lucid
+fi
+
+if [[ "${TOX_ENV}" == "pypy"]]; then
+    sudo apt-get install -y pypy
+
+    # This is required because we need to get rid of the Travis installed PyPy
+    # or it'll take precedence over the PPA installed one.
+    sudo rm -rf /usr/local/pypy/bin
+fi
+
+pip install tox coverage