Panic error when bucket is not fully created

panic: runtime error: integer divide by zero
[signal 0x8 code=0x1 addr=0x6168aa pc=0x6168aa]

goroutine 34 [running]:
github.com/couchbase/gocb/gocbcore.(*routeData).MapKeyVBucket(0xc8202740d0, 0xc8204f2920, 0xd, 0x10, 0x0, 0x0, 0xe35fc0)
/home/couchbase/jenkins/workspace/watson-unix/godeps/src/github.com/couchbase/gocb/gocbcore/routedata.go:134 +0x4a
github.com/couchbase/gocb/gocbcore.(*Agent).routeRequest(0xc820074200, 0xc8203c4360, 0x0, 0x0, 0x0)
/home/couchbase/jenkins/workspace/watson-unix/godeps/src/github.com/couchbase/gocb/gocbcore/agentrouting.go:445 +0x16f
github.com/couchbase/gocb/gocbcore.(*Agent).dispatchDirect(0xc820074200, 0xc8203c4360, 0x0, 0x0)
/home/couchbase/jenkins/workspace/watson-unix/godeps/src/github.com/couchbase/gocb/gocbcore/agentrouting.go:476 +0x3b
github.com/couchbase/gocb/gocbcore.(*Agent).dispatchOp(0xc820074200, 0xc8203c4360, 0x0, 0x0, 0x0, 0x0)
/home/couchbase/jenkins/workspace/watson-unix/godeps/src/github.com/couchbase/gocb/gocbcore/agentops.go:53 +0x47
github.com/couchbase/gocb/gocbcore.(*Agent).SetMeta(0xc820074200, 0xc8204f2920, 0xd, 0x10, 0xc8204b8000, 0x200, 0x200, 0xe5a720, 0x0, 0x0, ...)
/home/couchbase/jenkins/workspace/watson-unix/godeps/src/github.com/couchbase/gocb/gocbcore/agentops_internal.go:44 +0x5fc
github.com/couchbase/backup/couchbase.(*worker).asyncUpsertMeta(0xc8204d2000, 0xc8204f2910, 0xd, 0xc8204b8000, 0x200, 0x200, 0xe5a720, 0x0, 0x0, 0x0, ...)
/home/couchbase/jenkins/workspace/watson-unix/goproj/src/github.com/couchbase/backup/couchbase/pool.go:123 +0x1c6
github.com/couchbase/backup/couchbase.(*worker).doCouchbaseOpUnlocked(0xc8204d2000, 0xc8202b0cb0)
/home/couchbase/jenkins/workspace/watson-unix/goproj/src/github.com/couchbase/backup/couchbase/pool.go:111 +0x271
github.com/couchbase/backup/couchbase.(*worker).doCouchbaseOp(0xc8204d2000, 0xc8202b0cb0, 0x0, 0x0)
/home/couchbase/jenkins/workspace/watson-unix/goproj/src/github.com/couchbase/backup/couchbase/pool.go:79 +0x15a
github.com/couchbase/backup/couchbase.(*Callbacks).Mutation(0xc820313080, 0x1, 0x1, 0x143cb1f0fd720000, 0x0, 0x2000000000000, 0xc8204f27e0, 0xd, 0xd, 0xc8204b8000, ...)
/home/couchbase/jenkins/workspace/watson-unix/goproj/src/github.com/couchbase/backup/couchbase/callbacks.go:67 +0x288
github.com/couchbase/backup/archive.(*archiveDump).execute.func1(0xc8204f2220, 0x400, 0x1, 0xc8203c4000, 0xc82030a0c0, 0xc8204f2210, 0x0)
/home/couchbase/jenkins/workspace/watson-unix/goproj/src/github.com/couchbase/backup/archive/source.go:300 +0x981
created by github.com/couchbase/backup/archive.(*archiveDump).execute
/home/couchbase/jenkins/workspace/watson-unix/goproj/src/github.com/couchbase/backup/archive/source.go:311 +0x158

I'm not sure what the correct behavior should be in this case, but I don't think we should panic.