Update README.md and CHANGELOG.md.

CHANGELOG.md

@@ -2,12 +2,38 @@
 
 These are the release notes for JAX.
 
-## jax 0.1.58 (unreleased)
+## jax 0.1.59 (unreleased)
+
+## jax 0.1.58
 
 ### Breaking changes
 
+* JAX has dropped Python 2 support, because Python 2 reached its end of life on
+  January 1, 2020. Please update to Python 3.5 or newer.
+
 ### New features
 
-- Forward AD of while loop (https://github.com/google/jax/pull/1980)
+* Forward-mode automatic differentiation (`jvp`) of while loop
+  (https://github.com/google/jax/pull/1980)
+* New NumPy and SciPy functions:
+  * `jax.numpy.fft.fft2`
+  * `jax.numpy.fft.ifft2`
+  * `jax.numpy.fft.rfft`
+  * `jax.numpy.fft.irfft`
+  * `jax.numpy.fft.rfft2`
+  * `jax.numpy.fft.irfft2`
+  * `jax.numpy.fft.rfftn`
+  * `jax.numpy.fft.irfftn`
+  * `jax.numpy.fft.fftfreq`
+  * `jax.numpy.fft.rfftfreq`
+  * `jax.numpy.linalg.matrix_rank`
+  * `jax.numpy.linalg.matrix_power`
+  * `jax.scipy.special.betainc`
+* Batched Cholesky decomposition on GPU now uses a more efficient batched
+  kernel.
+
 
 ### Notable bug fixes
+
+* With the Python 3 upgrade, JAX no longer depends on `fastcache`, which should
+  help with installation.

README.md

@@ -9,6 +9,13 @@
 | [**Install guide**](#installation)
 | [**Reference docs**](https://jax.readthedocs.io/en/latest/)
 
+## Announcements
+
+* `jax` 0.1.58 has been released. As of `jax` 0.1.58, JAX has dropped Python 2
+  support. Please update to Python 3.5 or newer.
+
+## What is JAX?
+
 JAX is [Autograd](https://github.com/hips/autograd) and
 [XLA](https://www.tensorflow.org/xla),
 brought together for high-performance machine learning research.