BUG 2585 : Make Election Timeout Factor configurable

BUG 2585 : Make Election Timeout Factor configurable

Keeping the Heartbeat interval small and increasing the timeout
factor allows us to skip a few heartbeats if neccessary without
causing Followers to become Candidates.

Simply increasing the heartbeat interval has the negative effect
of causing replication messages for out-of date followers to go
slower so making the election factor configurable will be helpful
in keeping the cluster state stable.

Change-Id: Iae8105d65bba4a37987bfddb9f22d9d4d862a1fd
Signed-off-by: Moiz Raja <moraja@cisco.com>