…ent openwisp#525

changed the delete_old_radiusbatch_users management command to use days instead of months also modified tasks and tests to use days.

Fixes openwisp#525

… instead of months openwisp#525

Changed the delete_old_radiusbatch_users command to take in days in argument instead of months and modified tests and tasks accordingly.

Fixes openwisp#525

…tency

…tency

… as well openwisp#525

Added the option to delete users by specifying days or months.If nothing is provided 18 months will be taken as default.

Fixes openwisp#525

…-inconsistency

Made the suggested changes and added the testcase so both old and new command could be tested.

Fixes openwisp#525