Fix handling of ASK replies in RetryConn

See #18 .

v1.1.2

Remove mention that StartupNodes in Cluster struct needs to be master nodes (it can be replicas).

v1.1.1

Fixes the CI test.

v1.1.0

Builds with the new github.com/gomodule/redigo import path (a.k.a. v2.0 of redigo).

v1.0.0

This release works with github.com/garyburd/redigo, i.e. the redigo package version < 2.0.0 (before it moved to github.com/gomodule/redigo.