initial tree topology
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