Add Travis CI config.

//FREEBIE

.travis.yml

@@ -0,0 +1,7 @@
+language: android
+android:
+  components:
+    - platform-tools
+    - build-tools-19.1.0
+    - android-19
+    - extra-android-m2repository

README.md

@@ -1,4 +1,4 @@
-# TextSecure
+# TextSecure [![Build Status](https://travis-ci.org/WhisperSystems/TextSecure.svg?branch=master)](https://travis-ci.org/WhisperSystems/TextSecure)
 
 TextSecure is a messaging app for easy private communicate with friends.