Merge pull request #5 from fengjingchao/master

etcd layout: initial definition
add numberOfTasks interface to topology
initial tree topology
Merge pull request #6 from go-distributed/f

add numberOfTasks interface to topology
add tree_topo.go
Merge pull request #8 from go-distributed/topo_impl

add tree_topo.go
remove tree_topolgy.go as it was renamed as tree_topo.go
Merge remote-tracking branch 'upstream/master'
add test to tree_topo
add one more test
add task_config.go
localize the test data
use := instead of var in local scope
updated interface based on readme
updated interface based on readme
updated interface based on readme
add SetEpoch to framework as well
refix some typo
Merge pull request #7 from xiaoyunwu/master

initial tree topology
fix minor compile error