fix: documentation and version

1. Add api methods for managing spark history server.
2. Add submission_time and auto_termination_time fields in spark application list and details responses.

BREAKING CHANGE: The type of timestamp fields in Application response models has been changed to `datetime`.

Fields in Application and ApplicationGetResponse objects like start_time, end_time, finish_time will now have values of type `datetime` instead of plain strings.

Signed-off-by: Subin Shekhar <[email protected]>

Author: subinpc

CONTRIBUTING.md

@@ -5,7 +5,7 @@ or [Stack Overflow](http://stackoverflow.com/questions/ask?tags=ibm-cloud).
 
 # Issues
 If you encounter an issue with the project, you are welcome to submit a
-[bug report](<github-repo-url>/issues).
+[bug report](https://github.com/IBM/ibm-iae-python-sdk/issues).
 Before that, please search for similar issues. It's possible that someone has already reported the problem.
 
 # General Information