* [enhance] added Sales Invoice reference in Serial Number
* [patch] added test cases for Sales Invoice and added patch to copy sales invoice
* [minor] minor fixes in validate_serial_against_delivery_note
* [minor] fixes in sales invoice serial number validation
* Move allowance field in Item to the first section to apply it for both stock and non-stock items
* Fix status of invoices with negative outstanding, if no return entry
* get_value included in safe_eval
* deleted student batch creation tool
* Patch for deleting the doctype and config
* Changes in the student attendance
* Patch for renaming the student batch as student group
* Changes in the student attendance
* Change in the student attendance reports
- Absent student report
- Student Batch-wise attendance
- Student monthly attendance sheet
* Changes in the patch
* Changes in the course schedule
* Changes in the course scheduling tool
* Change in the assessment plan
* Changes in the assessment result tool
* Cleanup
* Changes in the api.py
* create student group from student batch
* delete student batch
* add patch
* remove student batch from config/schools.py
* Delete the depricated doctype with patch
* Changes in patch
* Changes as per PR