Update CONTRIBUTING.rst

Author: msm-sardar

CONTRIBUTING.rst

@@ -28,13 +28,13 @@ If you are reporting a bug, please include:
 Fix Bugs
 ~~~~~~~~
 
-Look through the Bitbucket issues for bugs. Anything tagged with "bug" and "help
+Look through the GitHub issues for bugs. Anything tagged with "bug" and "help
 wanted" is open to whoever wants to implement it.
 
 Implement Features
 ~~~~~~~~~~~~~~~~~~
 
-Look through the Bitbucket issues for features. Anything tagged with "enhancement"
+Look through the GitHub issues for features. Anything tagged with "enhancement"
 and "help wanted" is open to whoever wants to implement it.
 
 Write Documentation