This change reduces some unnecessary complexity in the library, Redis
commands do not change much after all. Developers can still implement
their own commands factory, inject new commands or override existing
ones. The "profile" client options has been renamed to "commands" and
it accepts instances of Predis\Command\FactoryInterface.
The test suite checks at runtime the version of the running instance
of Redis for integration tests to adapt itself automatically.
TravisCI environmenti run Redis 2.2 but we need Redis 2.4 to run the
integration tests in the test suite. For now we have simply disabled
the `connected` group of tests using a custom phpunit.xml file, we will
see later if it is worth building Redis on the fly with a `before_script`
directive in .travis.yml or just wait for a a new version of Redis to
be deployed on their VM images.
Daniele Alessandri