Network partition can cause multiple singleton masters to start.

SingletonService should be initialized with an initial value for minimum members. If enabled, this value can then grow dynamically as the number of nodes providing the service increases. As the number of nodes available to provide the service decreases, we should provide a WARNing if the quorum is in danger of not being reached (suggesting that this value may need to be adjusted manually) - and an ERROR if a quorum cannot be reached at all - suggesting a network partition.
The intention is to prevent the election of multiple singleton masters in the event of a network partition.