README: Remove pesky trailing whitespace.

Signed-off-by: Rogério Brito <rbrito@ime.usp.br>
README: Add travis badge.

We still need to know the language of the project before we fill in the
configuration for travis.

Signed-off-by: Rogério Brito <rbrito@ime.usp.br>
Merge pull request #3 from rbrito/travis

Looks good