Rehabilitate WaitTillHealthy for correct kademlia depth

[nolash]

swarm/network/simulation.WaitTillHealthy has been seen to flake after the kademlia calculations changed. All tests using the method have been deactivated.

The cause of flake needs to be resolved, and tests reactivated.

[nonsense]

It is actually flaky on master right now:

WARN [11-20|12:59:34.690|p2p/simulations/network.go:501] Can't stop node                          id=547f118d03d0b7b6 err="node not started"
ERROR[11-20|12:59:40.486|swarm/network/simulation/http.go:52] Error starting the HTTP server           error="http: Server closed"
WARN [11-20|12:59:42.072|swarm/network/protocol.go:227]       6d4236d3: handshake failed with remote peer 3dc81d18: Handshake error: EOF 
WARN [11-20|12:59:42.073|swarm/network/protocol.go:227]       3dc81d18: handshake failed with remote peer 6d4236d3: Handshake error: EOF 
WARN [11-20|13:00:12.099|swarm/network/protocol.go:227]       3dc81d18: handshake failed with remote peer 6d4236d3: Handshake error: EOF 
WARN [11-20|13:00:12.099|swarm/network/protocol.go:227]       6d4236d3: handshake failed with remote peer 3dc81d18: Handshake error: EOF 
WARN [11-20|13:00:42.111|swarm/network/protocol.go:227]       6d4236d3: handshake failed with remote peer 3dc81d18: Handshake error: EOF 
WARN [11-20|13:00:42.111|swarm/network/protocol.go:227]       3dc81d18: handshake failed with remote peer 6d4236d3: Handshake error: EOF 
WARN [11-20|13:01:12.132|swarm/network/protocol.go:227]       6d4236d3: handshake failed with remote peer 3dc81d18: Handshake error: EOF 
WARN [11-20|13:01:12.132|swarm/network/protocol.go:227]       3dc81d18: handshake failed with remote peer 6d4236d3: Handshake error: EOF 
--- FAIL: TestWaitTillHealthy (120.10s)
    kademlia_test.go:60: Node 6d4236d394df3d72d66dd2ed58e6fdfabad30854d610472f4f4eafcf5fa8da28
    kademlia_test.go:61: 
        =========================================================================
        Tue Nov 20 13:01:40 UTC 2018 KΛÐΞMLIΛ hive: queen's address: 6d4236
        population: 6 (9), MinProxBinSize: 2, MinBinSize: 2, MaxBinSize: 4
        000  3 c923 f4c8 88a9               |  5 c923 (0) e413 (0) f4c8 (0) f320 (0)
        ============ DEPTH: 1 ==========================================
        001  2 2581 0955                    |  3 0955 (0) 2581 (0) 3dc8 (6)
        002  1 4c81                         |  1 4c81 (0)
        003  0                              |  0
        004  0                              |  0
        005  0                              |  0
        006  0                              |  0
        007  0                              |  0
        008  0                              |  0
        009  0                              |  0
        010  0                              |  0
        011  0                              |  0
        012  0                              |  0
        013  0                              |  0
        014  0                              |  0
        015  0                              |  0
        =========================================================================
    kademlia_test.go:64: context deadline exceeded
WARN [11-20|13:01:40.653|p2p/simulations/network.go:501]      Can't stop node                          id=78dadbc7fa8d1514 err="node not started"
WARN [11-20|13:01:40.654|p2p/simulations/network.go:501]      Can't stop node                          id=97f89ff84a7f1bb9 err="node not started"
WARN [11-20|13:01:40.655|p2p/simulations/network.go:501]      Can't stop node                          id=e1ec61ba9746dfaf err="node not started"
WARN [11-20|13:01:43.501|p2p/simulations/network.go:501]      Can't stop node                          id=13e02a7d38271f4f err="node not started"
WARN [11-20|13:01:44.568|p2p/simulations/network.go:501]      Can't stop node                          id=c6d238ab3a7e95df err="node not started"
FAIL
coverage: 77.0% of statements
FAIL	github.com/ethereum/go-ethereum/swarm/network/simulation	130.668s

[nolash]

Health is still not correct; It will return healthy on mere 2 neighbors.

[zelig]

with ethereum/go-ethereum#19155 I think this can finally close