TF Quant Finance 0.0.1-dev9

Release notes:

• added example Colab "Introduction to TensorFlow Part 2 Debugging and Control Flow"
• TF Quant Finance now requires TensorFlow >= 1.14 and TensorFlow Probability >= 0.7.0

TF Quant Finance 0.0.1-dev8

Release notes:

• added sample Colab demonstrating root finding based on Brent's method;
• fixed import of diff op;

TF Quant Finance 0.0.1-dev7

Major Features and Improvements:

• added optimization algorithms: BFGS, L-BFGS, conjugate gradient descent, Nelder-Mead;
• added bond rate curve fitting using Hagan West interpolation;
• added antithetic random type for sampling Multivariate Normal Distribution;
• added several example Jupyter notebook example;
• fixed a number of bugs.

TF Quant Finance 0.0.1-dev6

Development version of TF Quant Finance library.