tests: add TestMultiNodeKillAllAndRecorveryAndRemoveLeader

This one breaks because it doesn't set joinIndex correctly.
fix(server): set joinIndex when recovered
fix(multi_node_kill_all_and_recovery_test): ensure cluster running
fix(remove_node_test): ensure cluster config is activated
fix(simple_snapshot_test): enlarge reasonable index range
Merge pull request #819 from unihorn/97

fix(server): joinIndex is not set after recovery from full outage