Fix trailing whitespace

CONTRIBUTING.md

@@ -9,14 +9,14 @@ We love your input! We want to make contributing to this project as easy and tra
 
 ## Reporting bugs
 
-To report bugs, please [open an issue on Github](https://github.com/devosoft/Empirical/issues) 
-clearly stating the observed (buggy) behavior (screenshots are encouraged), the desired behavior, 
-which operating system and compiler you're using (including version), and any additional information that might 
+To report bugs, please [open an issue on Github](https://github.com/devosoft/Empirical/issues)
+clearly stating the observed (buggy) behavior (screenshots are encouraged), the desired behavior,
+which operating system and compiler you're using (including version), and any additional information that might
 help us fix the bug. If possible, please provide a minimum example that reproduces the bug.
 
 ## Requesting features
 
-We welcome suggestions for how to make Empirical better! To give us your ideas, [open an issue on Github](https://github.com/devosoft/Empirical/issues). 
+We welcome suggestions for how to make Empirical better! To give us your ideas, [open an issue on Github](https://github.com/devosoft/Empirical/issues).
 
 ## Submitting new code and documentation
 
@@ -28,7 +28,7 @@ By working together, we can have a more versatile and robust library than any of
 Before writing new code, we reccomend opening an issue or commenting on an existing one to make sure that we're all on the
 same page and agree that your contribution will be consistent with Empirical's goals.
 
-In-depth guides to [getting started with Empirical development](https://empirical.readthedocs.io/en/latest/dev/getting-started.html), 
+In-depth guides to [getting started with Empirical development](https://empirical.readthedocs.io/en/latest/dev/getting-started.html),
 [coding guidelines for Empirical development](https://empirical.readthedocs.io/en/latest/dev/contribution-guidelines-and-review.html),
 [writing documentation](https://empirical.readthedocs.io/en/latest/dev/adding-documentation.html), and
 [writing tests](https://empirical.readthedocs.io/en/latest/dev/guide-to-testing.html) are available in the documentation.
@@ -42,7 +42,7 @@ As part of your pull request, please add yourself to the list of contributors in
 ## Code of Conduct
 
 Please note we have a [code of conduct](CODE_OF_CONDUCT.md) and follow it in all your interactions with the project.
-   
+
 ## License
 
 By contributing, you agree that your contributions will be released under [Empirical's MIT License](LICENSE.md).