Migrate to Python 3.9+ and modernize dependencies

[natyavidhan]

Migrates HateSonar from Python 2.7/3.4-3.6 to Python 3.9+.

Key Changes

• Removed Python 2 compatibility code (from __future__ imports, object base class)
• Fixed deprecated sklearn APIs (sklearn.externals.joblib, get_feature_names())
• Updated dependencies to modern versions (scikit-learn 0.24+, numpy 1.19+, pandas 1.1+)
• Updated LogisticRegression solver to saga (removed deprecation warning)
• Retrained model files with scikit-learn 1.7.1 (required for pickle compatibility)
• Added python_requires='>=3.9' in setup.py
• Version bump: 0.0.7 → 0.0.8

Testing

• All tests passing on Python 3.13
• Model accuracy maintained at ~91%
• No deprecation warnings

Breaking Changes

• Python 3.9+ required
• Models retrained (incompatible with v0.0.7)

[Hironsan]

Thank you.