fix: Revert "Merge pull request #176 from superfaceai/feat/send-email-with-attachements"

[jnv]

Description

Motivation and Context

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [ ] I have read the CONTRIBUTING document.
• [ ] I haven't repeated the code. (DRY)
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.

[jnv]

Closing in favor of #244