added tests checking if fields are in forms (dc,bo,li,su)
rm assets field from support's add-form & code cleaning
rm duplicated tests & code cleaning
rm 'form' string from supports' urls
Merge branch 'develop' of https://github.com/allegro/ralph_assets into rm-assets-field-form-support
added commas, commas, commas..
fixed flake8
Merge pull request #340 from xliiv/rm-assets-field-form-support

Deleted-assets-field