handle blank lines in roster upload

[hcientist]

upload student roster should be a bit more robust. apparently even our kind colleagues and collaborators have no compunction about violating the file format and sending us blank lines! 😆

Take a look over here

CPR-Music-Backend/teleband/courses/api/views.py

Lines 159 to 180 in 11f9bd1

	for name, username, password, grade in reader:
	if (name, username, password, grade) == (
	"fullname",
	"username",
	"password",
	"grade",
	):
	continue
	try:
	user = User.objects.get(username=username)
	if user.check_password(password):
	response["existing"].append(user)
	else:
	response["invalid"].append(
	{
	"name": name,
	"username": username,
	"password": password,
	"grade": grade,
	"reason": "Wrong password", # real bad
	}
	)

[devbazregari]

hi bro I hope you're doing great. do you want me to don't allow the student to send you blank credentials? like username or grade?