Our logic master repo is Hacker/master，Jerry and Lily folks this repo。
Someday，Lily added a new feature. Jerry want to tracking Lily’s changes, What do Jerry’s do?
1, fetch the changes from Lily
git remote add Lily [Lily’s repo address]
git fetch Lily
2, add a tracking branch named “track-Lily” to track the changes from Lily
git branch track-Lily –track Lily/master
3，switch working branch to “track-Lily”
git branch –a #list all of branches
git checkout track-Lily #switch the branch to Lily’s
After Jerry review the Lily’s code, then Jerry want to back to himself work, so:
4, switch back to Jerry’s branch
git checkout master
git branch -a