Merge pull request #26 from travelton/master

Added tip4commit on README.

README.md

@@ -175,3 +175,14 @@ If you find a bug, please submit the issue in Github directly.
 
 As always, if you need additional assistance, drop us a note at 
 [support@mailgun.com](mailto:support@mailgun.com).
+
+Community Donations
+-------------------
+
+This project supports community developers via http://tip4commit.com. If participating, developers will receive a Bitcoin tip for each commit that is merged to the master branch. 
+
+Note: Core developers, who receive a tip, will donate those tips back to the project's tip jar. This includes all Mailgun employees. While Mailgun sponsors this project, it does not accept or receive any tips.
+
+If you'd like to support the community, add Bitcoins to the tip jar: 1JnvwDXjGhbCSna8XQiPkwLw9WCvEAy1DH. 
+
+[![tip for next commit](http://tip4commit.com/projects/214.svg)](http://tip4commit.com/projects/214)