Fix seed file, by adding manually accounts

Add account_create
Merge pull request #53 from Selectra-Dev/seeds_fix

Fix seed file, by adding manually accounts
Add hours to offers
Merge pull request #54 from Selectra-Dev/seeds_fix

Add hours to offers
Adding school statistics for school admins (ref #13)
Adding school statistics for admins (ref #14)
Adding callback requests for operators (fix #19)