Update release notes.

Author: tshead2

docs/release-notes.rst

@@ -7,6 +7,28 @@
 Release Notes
 =============
 
+Toyplot 0.4.0 - January 27, 2014
+--------------------------------
+
+* Began continuous integration testing.
+* Switched from ost.io to https://gitter.im/sandialabs/toyplot for support requests.
+* Made the HTML backend the primary renderer.
+* Improved logarithmic tick formatting and customization.
+* Increased consistency between the fill() and plot() APIs.
+* Simplified the way colors are inherited for line plots and scatter plots.
+* Added basic functionality for reading and writing CSV files.
+
+  * Note: for pedagical purposes only - Toyplot is *not* a data manipulation tool!
+
+* Ongoing improvements to the table axes API:
+
+  * Added support for table titles.
+  * Added support for hiding table headers.
+  * Table headers can have multiple rows.
+  * Ensure that visible cells are rendered in a deterministic order.
+  * Create a default grid line between table header and body.
+  * Added support for user-configurable gaps between cells.
+
 Toyplot 0.3.0 - November 5, 2014
 --------------------------------