Add a "stop time" feature to chutney
Currently, chutney's test-network.sh waits for the following amount of time:
- a mandatory 15 seconds for the consensus to form
- up to 60 seconds while verifying the network And then it terminates the network.
But sometimes I want chutney to hang around for several minutes, or even forever.
There should be an option / environmental variable for this "stop time" in test-network.sh.