Removed unused references from test project and added nunit as reference instead of adding from nuget
Modified NHibernateSessionConfiguration and
Added a test to fetch a student from database and to test the mappings
Added GetAll method and a test to fetch all students from database
Changed student repository to base repository
Seperated out session creation from BaseRepo
Added a new class to rollback the transaction in tests
Added a new method to save or update a domain(student)
Added methods to delete a domain (student) and a method to commit the changes to database
Moved the helper classes to respective folders