JIRA: https://jira.spring.io/browse/INT-3795
Previously, a `CachingClientConnectionFactory` could wrap `FailoverClientConnectionFactory` instances.
It was not possible to wrap `CachingClientConnectionFactory` instances in a `FailoverClientConnectionFactory`.
The failover logic only failed over when an `IOException` occurred, whereas the CCCF wrapped the IOException
in a `MessagingException`.
- Catch all exceptions in the failover logic
- Add real TCP test cases for both scenarios
- test failover when a connection is closed
- test failover when the first factory cannot connect at all
INT-3795: Polishing - Fix Test Race
Revert `.travis.yml` changes
0ce5f12342