记录一些常用的git别名，提交代码再也不用敲那么多键了
co = checkout
cia = commit -am
st = status
br = branch
sbu = submodule update --recursive
sbl = submodule foreach git log -1 --oneline
sbf = submodule foreach git fetch
sbp = submodule foreach git pull
sbst = submodule foreach git status
stp = stash pop
stl = stash list
sts = stash show
stsp = stash show -p
