Update README.md

ch01/README.md

@@ -66,11 +66,11 @@ Throughout this book, we will mainly use NumPy's multi-dimensional arrays to sto
 
 The version numbers of the major Python packages that were used for writing this book are listed below. Please make sure that the version numbers of your installed packages are equal to, or greater than, those version numbers to ensure the code examples run correctly:
 
-- [NumPy](http://www.numpy.org) >= 1.16.4
-- [SciPy](http://www.scipy.org) >= 1.2.1
-- [scikit-learn](http://scikit-learn.org/stable/) >= 0.21.1
+- [NumPy](http://www.numpy.org) >= 1.17.4
+- [SciPy](http://www.scipy.org) >= 1.3.1
+- [scikit-learn](http://scikit-learn.org/stable/) >= 0.22.0
 - [matplotlib](http://matplotlib.org) >= 3.1.0
-- [pandas](http://pandas.pydata.org) >= 0.24.2
+- [pandas](http://pandas.pydata.org) >= 0.25.3
 
 ## Python/Jupyter Notebook
 
@@ -115,4 +115,4 @@ and similar to starting Jupyter Notebooks, you can run the command
 
     $ jupyter lab
 
-in your command line terminal to launch a Jupyter Lab session in your browser. For more information about the Jupyter Lab project, please visit the official documentation at https://jupyterlab.readthedocs.io/en/stable/,
+in your command line terminal to launch a Jupyter Lab session in your browser. For more information about the Jupyter Lab project, please visit the official documentation at https://jupyterlab.readthedocs.io/en/stable/,