Merge pull request #4 from yifan-gu/master

add a simple bench for send/receiver, small modification to send_test
Merge pull request #5 from yifan-gu/master

change addr string to addr struct in Receiver{}
feat(receiver.go) add sendto
Merge pull request #6 from xiangli-cmu/master

feat(receiver.go) add sendto
Merge branch 'master' of github.com:go-epaxos/message