Requirement: functionality that will reconfigure
a OBSERVER to become a voting member and vice versa.
Example of usage:
1. Maintain the Quorum size without changing the cluster size - in a 5
node cluster with 2 observers, I decide to decommission a voting
member. Then, I would like to configure one of my observers to be a
follower without any down time.
2. Added a new server to the cluster that has better resources than
one of the voting peers. Make the new node as voting peer and the old
one as observer.
3. Reduce the size of voting member for performance reasons.