v1.13.9.0

v1.13.9.0

New features

1. Add Logarithmic integral functions
2. Add Exponental integral functions
3. Add Sine and Cosine integral functions
4. Add missing Ostap::Math::LegendreSum[X]::integral methods

Backward incompatible

Bug fixes

1. fix a typo in graphs.py (thanks to Dima Pereima!)