Tests

Tests need to be added. A mirror repository is set up on Github so that tests can be run directly against Elasticsearch via Travis-CI.

I'll try to get a reasonable amount of coverage on current features done in the next couple of weeks. Ideally, any new features added will need to come with tests before being committed.

The matrix on Travis-CI is testing PHP versions 5.3, 5.4, and 5.5, each with composer_manager and libraries options for using the Elastica library. PHP 5.5 is set to accept failure.