strip trailing whitespace from readme

Author: drusepth

README.rdoc

@@ -3,7 +3,7 @@
 {<img src="https://codeclimate.com/github/indentlabs/notebook/badges/coverage.svg" />}[https://codeclimate.com/github/indentlabs/notebook/coverage]
 {<img src="http://inch-ci.org/github/indentlabs/notebook.svg?branch=master" alt="Inline docs" />}[http://inch-ci.org/github/indentlabs/notebook]
 
-== What is Notebook.ai? 
+== What is Notebook.ai?
 
 see {live website}[http://notebook.ai/]