Mongoose Deprecation Warning

[stanleyowen]

Describe the bug
As on the latest version of mongoose dependency, which is v5.x, there are some deprecations made on this dependency to improve the consistency across all MongoDB Driver etc. Therefore, there are some deprecations as described here:

mongoose.set('useNewUrlParser', true);
mongoose.set('useFindAndModify', false);
mongoose.set('useCreateIndex', true);
mongoose.set('useUnifiedTopology', true);
Replace update() with updateOne(), updateMany(), or replaceOne()
Replace remove() with deleteOne() or deleteMany().
Replace count() with countDocuments(), unless you want to count how many documents are in the whole collection (no filter). In the latter case, use estimatedDocumentCount().

Expected behavior
Replace all the deprecated with the alternative in order to avoid error.

Desktop (please complete the following information):

• OS: Windows 10 OS Version 2009 (Build 19042.985)
• Browser Chrome
• Version 91.0.4472.77