Write unit tests for 'Категорії для фанатів'

[mythter]

• test for creating new category
• test converting image to grey colour
• test for editing category
• check text amount restrictions in input
• check also functionality that when required fields are the same then existing news should be updated instead of created

For file uploader use image from assets (folder for_tests)

Component to put tests on:

Mock all needed requests as create, update, get category