implement Scylla database

vendor/github.com/hailocab/go-hostpool/README.md

@@ -0,0 +1,17 @@
+go-hostpool
+===========
+
+A Go package to intelligently and flexibly pool among multiple hosts from your Go application.
+Host selection can operate in round robin or epsilon greedy mode, and unresponsive hosts are
+avoided.
+Usage example:
+
+```go
+hp := hostpool.NewEpsilonGreedy([]string{"a", "b"}, 0, &hostpool.LinearEpsilonValueCalculator{})
+hostResponse := hp.Get()
+hostname := hostResponse.Host()
+err := _ // (make a request with hostname)
+hostResponse.Mark(err)
+```
+
+View more detailed documentation on [godoc.org](http://godoc.org/github.com/bitly/go-hostpool)