(Maint) Whitespace cleanup of CONTRIBUTING.md

Just noticed some whitespace errors.  This is a whitespace only change
that removes trailing whitespace from CONTRIBUTING.md

CONTRIBUTING.md

@@ -5,25 +5,26 @@ access the huge number of platforms and myriad configurations for running
 puppet. We want to keep it as easy as possible to contribute changes that
 get things working in your environment. There are a few guidelines that we
 need contributors to follow so that we can have a chance of keeping on
-top of things. 
+top of things.
 
 ## Getting Started
 
 * Make sure you have a [Redmine account](http://projects.puppetlabs.com)
 * Make sure you have a [GitHub account](https://github.com/signup/free)
-* Submit a ticket for your issue, assuming one does not already exist. 
+* Submit a ticket for your issue, assuming one does not already exist.
   * Clearly describe the issue including steps to reproduce when it is a bug.
   * Make sure you fill in the earliest version that you know has the issue.
 * Fork the repository on GitHub
-  
+
 ## Making Changes
 
 * Create a topic branch from where you want to base your work.
-  * This is usually the master branch. 
-  * Only target release branches if you are certain your fix must be on that branch.
+  * This is usually the master branch.
+  * Only target release branches if you are certain your fix must be on that
+    branch.
 * Make commits of logical units.
 * Check for unnecessary whitespace with "git diff --check" before committing.
-* Make sure your commit messages are in the proper format. 
+* Make sure your commit messages are in the proper format.
 
 ````
     (#Ticket Number) What you are changing with this commit
@@ -42,7 +43,7 @@ top of things.
 * Submit a pull request to the repository in the puppetlabs organization.
 * Update your Redmine ticket to mark that you have submitted code and are ready for it to be reviewed.
   * Include a link to the pull request in the ticket
-   
+
 # Additional Resources
 
 * [More information on contributing](http://links.puppetlabs.com/contribute-to-puppet)