More fixes for 1.2.16
Fixed examples and typo
We need C* running on Travis
Attempt to fix async test on Travis
Second attempt to fix Travis
Check if session implements com.datastax.driver.core.Session, not is one

Cluster#connect always returns an instance of SessionManager, which
implements Session, so we should check for the interface, not concrete
implementation

Should have belonged to @arr-ee, I just fixed it in a different way initially. Avoiding merge conflicts.