Fix typo and update minimal version of scipy
Signed-off-by: Oktai Tatanov <oktai.tatanov@gmail.com>

**Collection**: [DOC]

# Changelog 
- fix typo in README
- fix minimal version for SciPy (it is necessary to use `scipy.stats`
  
**PR Type**:
- [ ] New Feature
- [x] Bugfix
- [ ] Documentation

