Add build and coverage badges (#115)

Author: Mariatta

README.rst

@@ -1,6 +1,10 @@
 miss-islington
 ==============
 
+.. image:: https://travis-ci.org/python/miss-islington.svg?branch=master
+    :target: https://travis-ci.org/python/miss-islington
+.. image:: https://codecov.io/gh/python/miss-islington/branch/master/graph/badge.svg
+    :target: https://codecov.io/gh/python/miss-islington
 .. image:: https://img.shields.io/badge/code%20style-black-000000.svg
     :target: https://github.com/ambv/black