Merge pull request apache#1198 from r39132/master

Updating the Bug Reporting protocol in the Contributing.md file

CONTRIBUTING.md

@@ -26,12 +26,13 @@ little bit helps, and credit will always be given.
 
 Report bugs through Github
 
-If you are reporting a bug, please include:
+If you are reporting a bug, you MUST provide all of the following or the bug will be closed :
 
--   Your operating system name and version.
--   Any details about your local setup that might be helpful in
-    troubleshooting.
--   Detailed steps to reproduce the bug.
+-   Version of Airflow (e.g. a release version, running your own fork, running off master -- provide a `git log` snippet)
+-   Example code to reproduce the bug (as a code snipper in markdown)
+-   Screen shots of your DAG's graph and tree views
+-   Stack trace if applicable
+-   Your operating system name and version
 
 ### Fix Bugs