added travis-ci support

Thee only thing that remains is to:

- go to https://travis-ci.org/,
- click SignUp with Github (top, right),
- go to accounts (top, right), 
- push the 'sync now' button and enable tinympl repo.

As you may see, the current version [doesn't seem to work with clang compiler](https://travis-ci.org/ptomulik/tinympl/builds/28068397). I'll investigate it.