Add TravisCI support.

Summary:
Add TravisCI support.

This makes it so test status shows up in the README.md and on pull requests.

We use TravisCI for xctool as well.
diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..a8cbc23
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,25 @@
+language: java
+jdk:
+  - oraclejdk7
+before_install:
+  # Make sure apt is up to date.
+  - sudo apt-get update -qq
+  # Travis is on 64bit and there will be a cryptic aapt error w/o these libs.
+  - if [ `uname -m` = x86_64 ]; then sudo apt-get install -qq --force-yes libgd2-xpm ia32-libs ia32-libs-multiarch > /dev/null; fi
+  # Download the Android sdk and unzip.
+  - wget http://dl.google.com/android/android-sdk_r22.2.1-linux.tgz
+  - tar -zxf android-sdk_r22.2.1-linux.tgz
+  # Set up the sdk environment.
+  - export ANDROID_HOME=`pwd`/android-sdk-linux
+  - export PATH=${PATH}:${ANDROID_HOME}/tools
+  - export PATH=${PATH}:${ANDROID_HOME}/platform-tools
+  - export PATH=${PATH}:${ANDROID_HOME}/build-tools
+  # Install the sdk bits we need.
+  - ./scripts/travisci_install_android_sdk.sh > /dev/null
+  # Download the Android ndk and unzip.
+  - wget http://dl.google.com/android/ndk/android-ndk-r9-linux-x86_64.tar.bz2
+  - tar xf android-ndk-r9-linux-x86_64.tar.bz2
+  - mv android-ndk-r9 android-ndk-linux
+  # Set up the ndk environment.
+  - export ANDROID_NDK=`pwd`/android-ndk-linux
+  - export PATH=${ANDROID_NDK}:${PATH}
diff --git a/README.md b/README.md
index 962f058..5260e1b 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,8 @@
 Buck is an Android build tool. To see what Buck can do for you,
 check out the documentation at <http://facebook.github.io/buck/>.
 
+[![Build Status](https://travis-ci.org/facebook/buck.png)](https://travis-ci.org/facebook/buck)
+
 Installation
 ------------
 
diff --git a/scripts/travisci_install_android_sdk.sh b/scripts/travisci_install_android_sdk.sh
new file mode 100755
index 0000000..47ad474
--- /dev/null
+++ b/scripts/travisci_install_android_sdk.sh
@@ -0,0 +1,17 @@
+#!/bin/bash
+set -x
+
+# Values from `android list sdk --extended --all`
+(while :
+do
+    echo y
+    sleep 2
+ done) | android update sdk --force --no-ui --all --filter \
+tools,\
+platform-tools,\
+build-tools-18.1.1,\
+android-16,\
+addon-google_apis-google-16,\
+android-18,\
+addon-google_apis-google-18,\
+extra-android-support