DOC: Updated whatsnew

docs/source/whatsnew/0.8.4.txt

@@ -55,6 +55,7 @@ Build
 * Makes zipline install requirements more flexible (:issue:`825`).
 * Use ``versioneer`` to manage the project ``__version__`` and setup.py version
   (:issue:`829`).
+* Fixed coveralls integration on travis build (:issue:`840`).
 
 Documentation
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