CHANGELOG date, README Colab section

Author: jonmmease

CHANGELOG.md

@@ -2,7 +2,7 @@
 All notable changes to `jupyter-dash` will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/).
 
-## 0.3.0 - ???
+## 0.3.0 - 2020-07-21
 ### Added
  - Added suport for using JupyterDash in Google Colab ([#27](https://github.com/plotly/jupyter-dash/pull/27))
  - Added support for installing JupyterDash from git using pip: (e.g. `pip install git+https://github.com/plotly/jupyter-dash.git@master`)

README.md

@@ -28,6 +28,12 @@ $ jupyter lab build
 
 To check that the extension is installed properly, call `jupyter labextension list`.
 
+## Colab support
+As of version 0.3.0, `JupyterDash` works in Colab with no additional configuration. Just install `jupyter-dash` using pip in a Colab notebook cell
+```
+!pip install jupyter-dash
+```
+
 # Features
 To learn more about the features of JupyterDash, check out the [announcement post](https://medium.com/plotly/introducing-jupyterdash-811f1f57c02e).