Adding Feature: when all nodes reaches fail status, and slaves wakes up. promoting it as master

there is 3 nodes A,B,C

A(M), B(S), C(S)
A fails, B Promoted
A(F), B(M), C(S)
B fails, C Promoted
A(F), B(F), C(M)
C fails
A(F), B(F), C(F)
and if B or C revives sentinel can't detect.
A(F),B(F),C(S)

This patch will promote any slaves that revivives.