cronjob api changes

[sasi2312]

1. Github API endpoint changes 2.Changed existing code to with respective response get from above

[sasi2312]

These keys are not exist in github API resposne "roster_identifier" "starter_code_url" ....Im making these as empty....comment ur sugesstion @KDwevedi

Have grade as null for below users:

• 'IAlgorithmia',
• 'RiyaRaj28',
• 'SaumyaSamagra',
• 'Shruti3004',
• 'Ranjanmangla1',
• 'karntrehan',
• 'Omkar309',
• 'Param1304',
• 'Vaibhavn07',
• 'PraveenRepswal',
• 'Sayan2908',
• 'sujanMidatani7',
• 'simran142002',
• 'limitlessBrain1',
• 'pankaj-2503',
• 'Poojithaduggireddy',
• 'kabirrajsingh',
• 'mohdyasirkn',
• 'KK1215'