raft: update raft paper link (previous link deprecated)

raft/README.md

@@ -3,7 +3,7 @@
 Raft is a protocol with which a cluster of nodes can maintain a replicated state machine.
 The state machine is kept in sync through the use of a replicated log.
 For more details on Raft, see "In Search of an Understandable Consensus Algorithm"
-(https://ramcloud.stanford.edu/raft.pdf) by Diego Ongaro and John Ousterhout.
+(https://raft.github.io/raft.pdf) by Diego Ongaro and John Ousterhout.
 
 This Raft library is stable and feature complete. As of 2016, it is **the most widely used** Raft library in production, serving tens of thousands clusters each day. It powers distributed systems such as etcd, Kubernetes, Docker Swarm, Cloud Foundry Diego, CockroachDB, TiDB, Project Calico, Flannel, and more.
 

raft/doc.go

@@ -19,7 +19,7 @@ defined in the raftpb package.
 Raft is a protocol with which a cluster of nodes can maintain a replicated state machine.
 The state machine is kept in sync through the use of a replicated log.
 For more details on Raft, see "In Search of an Understandable Consensus Algorithm"
-(https://ramcloud.stanford.edu/raft.pdf) by Diego Ongaro and John Ousterhout.
+(https://raft.github.io/raft.pdf) by Diego Ongaro and John Ousterhout.
 
 A simple example application, _raftexample_, is also available to help illustrate
 how to use this package in practice:

raft/raft_paper_test.go

@@ -14,7 +14,7 @@
 
 /*
 This file contains tests which verify that the scenarios described
-in the raft paper (https://ramcloud.stanford.edu/raft.pdf) are
+in the raft paper (https://raft.github.io/raft.pdf) are
 handled by the raft implementation correctly. Each test focuses on
 several sentences written in the paper. This could help us to prevent
 most implementation bugs.