Add very basic Travis CI support.

.travis.yml

+language: python
+python:
+  - "2.6"
+  - "2.7"
+
+# No need to install any deps.
+install: true
+
+before_install:
+  # Need this for the git tests to succeed.
+  - git config --global user.email "spack@example.com"
+  - git config --global user.name "Test User"
+
+script:
+  - . share/spack/setup-env.sh
+  - spack test
+
+notifications:
+  email:
+    recipients:
+      - tgamblin@llnl.gov
+    on_success: change
+    on_failure: always

README.md

 ![image](share/spack/logo/spack-logo-text-64.png "Spack")
 ============
 
+[![Build Status](https://travis-ci.org/scalability-llnl/spack.png?branch=develop)](https://travis-ci.org/scalability-llnl/spack)
+
 Spack is a package management tool designed to support multiple
 versions and configurations of software on a wide variety of platforms
 and environments. It was designed for large supercomputing centers,