Cryptosteganography

Added

- Show help when CLI command is empty or invalid
- Improved tests for empty and invalid CLI commands

Fixed

- Fixed Python version specification in the publish workflow
- Corrected Codecov command

Changed

- Updated several libraries to their latest versions
- Modified code and tests to accommodate library updates
- Switched from TravisCI to GitHub Actions for CI/CD workflows

- Fix issue with pillow and update dependencies

- Show help when CLI command is empty or invalid

- Improve CLI organtization
- Improve code maintainability

- Improve code organization
- Add a complete test suite
- Add TravisCI support
- Add LGTM support
- Add Coveralls support

- Update files to match pypi requirements