[backend] CSRF protection

[abdulmoizeng]

Steps

• GET request and other safe methods should be side effect free (as per https://tools.ietf.org/html/rfc7231.html#section-4.2.1)
• Follow steps as define in below mentioned link to make un secure methods (POST, DELETE, PUT etc) secure

link to follow : https://docs.djangoproject.com/en/2.1/ref/csrf/