Add travis ci testing configuration

This PR should provide base for an automated travis testing.  

It works by adding:

1. the main ```.travis.yml```configuration
2. a shell script using xctool to build & test the application provided
3. a shared scheme needed by the xctool needed by the tool to compile (the project is compiled by the travis user in the CI environment)

It also adds the travis badge in the README.markdown, but obviously it would have to be modified before merging to point to your repository. 

Let me know if I can improve the build/test process somehow.