add functions/vendor files

vendor/github.com/fsouza/go-dockerclient/travis-scripts/install-docker.bash

@@ -0,0 +1,19 @@
+#!/bin/bash -x
+
+# Copyright 2016 go-dockerclient authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+if [[ $TRAVIS_OS_NAME == "linux" ]]; then
+	sudo stop docker || true
+	sudo rm -rf /var/lib/docker
+	sudo rm -f `which docker`
+
+	set -e
+	sudo apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 --recv-keys 58118E89F3A912897C070ADBF76221572C52609D
+	echo "deb https://apt.dockerproject.org/repo ubuntu-trusty main" | sudo tee /etc/apt/sources.list.d/docker.list
+	echo "deb https://apt.dockerproject.org/repo ubuntu-trusty testing" | sudo tee -a /etc/apt/sources.list.d/docker.list
+	sudo apt-get update
+	sudo apt-get install docker-engine=${DOCKER_VERSION}-0~ubuntu-$(lsb_release -cs) -y --force-yes -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold"
+	sudo start docker || true
+fi