Automatically create the instructor role once an instructor is created.

[fderyckel]

Once an instructor is created, one should create the role of instructor.
If instructor is set to left then role should be updated to not be an instructor anymore \

Taken from Employee

def update_user(self):
	# add employee role if missing
	user = frappe.get_doc("User", self.user_id)
	user.flags.ignore_permissions = True

	if "Employee" not in user.get("roles"):
		user.append_roles("Employee")