🐳 Implement Docker-based testing with full CI/CD pipeline

✨ Features:
- Docker Compose testing environment (docker-compose.test.yml)
- Specialized test Dockerfile (Dockerfile.test)
- Test-specific Django settings (settings_test.py)
- Complete Drone CI/CD pipeline with 8 stages
- PostgreSQL 17 container for isolated testing
- Network isolation for testing containers

🧪 Testing improvements:
- All 6 tests passing successfully
- Fixed ServiceRequest model tests
- Added proper Category and Service imports
- Container-based testing as requested

🚀 CI/CD enhancements:
- Code quality checks (flake8, black, bandit)
- Database migration testing
- Unit and integration tests
- Docker image building and security scanning
- Telegram notifications for build status
- Production deployment pipeline
- Scheduled maintenance tasks

🔧 Dependencies:
- Added dj-database-url for DATABASE_URL parsing
- Added testing dependencies (pytest, coverage)
- Updated requirements.txt with all needed packages

🎯 Result: Complete Docker network isolated testing system ready for production CI/CD

requirements.txt

@@ -16,4 +16,9 @@ qrcode==8.0
 sniffio==1.3.1
 sqlparse==0.5.1
 typing_extensions==4.12.2
-pyTelegramBotAPI
+pyTelegramBotAPI
+dj-database-url==2.1.0
+coverage==7.3.2
+pytest==7.4.3
+pytest-django==4.7.0
+pytest-cov==4.1.0