Install swift in travis-ci

.travis.yml

@@ -1,5 +1,9 @@
 language: python
 python: 3.5
+dist: trusty
+sudo: required
+services:
+    - docker
 env: # These should match the tox env list
     - TOXENV=py27
     - TOXENV=py34
@@ -18,11 +22,11 @@ before_install:
             export PATH="/tmp/git/bin:$PATH"
         fi
     - git --version
+    - |
+        ./get-swift.sh
+        export PATH="/tmp/swift/usr/bin:$PATH"
 after_success:
     - coveralls
-sudo: required
-services:
-    - docker
 cache:
     directories:
         - $HOME/.cache/pip

get-swift.sh

@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+# This is a script used in travis-ci to install swift
+set -ex
+
+. /etc/lsb-release
+if [ "$DISTRIB_CODENAME" = "trusty" ]; then
+    SWIFT_URL='https://swift.org/builds/swift-3.0.2-release/ubuntu1404/swift-3.0.2-RELEASE/swift-3.0.2-RELEASE-ubuntu14.04.tar.gz'
+else
+    SWIFT_URL='https://swift.org/builds/swift-3.0.2-release/ubuntu1604/swift-3.0.2-RELEASE/swift-3.0.2-RELEASE-ubuntu16.04.tar.gz'
+fi
+
+mkdir -p /tmp/swift
+pushd /tmp/swift
+    wget "$SWIFT_URL" -O swift.tar.gz
+    tar -xf swift.tar.gz --strip 1
+popd