update README.md
update requirements.txt
add AUTHORS and CHANGES
change command to be optional
add ModelMixin
rename utils.py to helpers.py, move functions in template.py to app.py
remove some useless of meaningless function
change common opertion functions to classmethods. Documented master/form.py
fix after rename
updateg
Merge branch 'refactor/clean-codes' into develop
add test case