Merge pull request #233 from theponti/master

Merge from master
Merge pull request #234 from theponti/feature/category-directive

Feature/category directive
Move handling of success and error responses into API service
Refactor API service
Fix references to Model in application controller functions
Add missing semicolon
Switch to sending object as response "{ data: [] }"
Fix whitespace
Merge remote-tracking branch 'origin/feature/category-directive' into feature/category-directive
Able to assign category to new and existing backpacks
Merge pull request #236 from theponti/feature/category-directive

Feature/category directive
Merge pull request #235 from theponti/development

Development