Merge pull request #6 from kbaba1001/article_crud

fix delete tables order

DRY

add delete article handler

create feature of deleting articles

automatic update timestamps(updated_at)

add update article handler

wip

change db connection in dev

i tried not to use ataraxy/result parameters

change articles handler parameters interface

change users handler parameters interface

fix user boundary test

change params interface

validate unique email