Merge pull request #38 from xiangli-cmu/master

bump deps
Merge pull request #39 from xiangli-cmu/master

fix(readme) typo in readme delect section
feat(delete_command.go) add dir flag
feat(rmdir) add rmdir command; rename delete to rm
doc(delete->rm)
Merge pull request #40 from xiangli-cmu/delete_dir

feat(delete_command.go) add dir flag
refactor rename create to mk
refactor rename create to mk
Merge pull request #41 from xiangli-cmu/create_to_mk

refactor rename create to mk
merge master