docs: Update sidebar with new badges and project summary.

docs/.templates/sidebar.html

@@ -1,13 +1,14 @@
 <p>
-  Display any data in pretty printed tabular format with ease using tableD.
-</p>
-<p>
-  <iframe src="https://readthedocs.org/projects/tabled/badge/?version=latest"
-  allowtransparency="true" frameborder="0" scrolling="0" width="200" height="20">
-  </iframe>
-</p>
-<p>
-  <iframe src="https://img.shields.io/badge/license-MIT-blue.svg"
-  allowtransparency="true" frameborder="0" scrolling="0" width="200" height="20">
-  </iframe>
+  tableD transforms your raw data into beautifully formatted tables. Can I
+  call it <b><i>Tables for Humans?</i></b>
 </p>
+
+<h3>
+  Project status:
+</h3>
+<hr>
+<img src="https://travis-ci.org/tommyip/tabled.svg?branch=master" alt="Tavis CI" border="0">
+<img src="https://coveralls.io/repos/github/tommyip/tabled/badge.svg?branch=master" alt="Coveralls">
+<img src="https://readthedocs.org/projects/tabled/badge/?version=latest" alt="Read The Docs">
+<img src="https://img.shields.io/badge/license-MIT-blue.svg" alt="MIT license">
+<hr>