change default ports

[eolesinski]

This PR addresses issue #97 by updating the port numbers used in the raft_test.cpp unit tests to a higher range (29800-29802) to avoid conflicts with commonly used ports.

Port conflicts with 5000 are frequent, especially with the docker-registry and Apple's AirPlay Receiver on MacOS. To address this issue, the default ports are updated to 298xx, following the convention outlined in #259.

Tested: tested by running ./scripts/test.sh