Adding more tests and bug fixes

protocols/bgp/server/bmp_router.go

protocols/bgp/server/bmp_router_test.go

protocols/bgp/server/bmp_server.go

protocols/bgp/server/bmp_server_test.go

protocols/bgp/server/fsm_address_family.go

protocols/bmp/packet/decode.go

protocols/bmp/packet/peer_down.go

routingtable/adjRIBIn/adj_rib_in.go