Travis CI for SQLite

I have got Travis set up with a third matrix entry: perl 5.14 and SQLite database.

Results at: https://travis-ci.org/Anacode/ensembl/builds/21246639

The first few commits, and af603ab, are ensuring that tests pass under SQLite as there had been a bit of drift.

The latter commits add the SQLite tests into the Travis setup.

It'd be great to get this merged in. Thanks!