simple sendAccept and test
Merge branch 'dev' of github.com:go-epaxos/epaxos into dev
Merge pull request #9 from fengjingchao/dev

finish simple recvPreAccept
before merge
sendaccept and acceptreply, add info in instance for bookkeeping, add ballot in instance
put instance info in instance.go
Merge pull request #8 from yifan-gu/dev

simple sendAccept and test
add fastquorum size