remove unused Connection methods
make Connection's isBinding return false for empty bindings
move tests into their own directory and tell phpunit about it
fix a compatibility issue with php 5.3

In php 5.3 we are not allowed to access resulting arrays items
directly, i.e. $this->getArray()[1]. So we need to extract that on its
own through the assigned variable.
update database connection configuration for tests

include the default configuration
ask Travis to start the neo4j service for the tests to work