removed default grades
Merge branch 'master' of https://github.com/HeesungSohn/SecureGradingSystem
Merge branch 'master' of https://github.com/HeesungSohn/SecureGradingSystem
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Merge branch 'master' of https://github.com/HeesungSohn/SecureGradingSystem
Merge branch 'master' of https://github.com/HeesungSohn/SecureGradingSystem
Merge branch 'master' of https://github.com/HeesungSohn/SecureGradingSystem
Merge branch 'master' of https://github.com/HeesungSohn/SecureGradingSystem
now we save changes permanently on the server