Update connect-mongo to ^3.0.0

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
connect-mongo	dependencies	major	^2.0.1 -> ^3.0.0

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Release Notes

jdesboeufs/connect-mongo

v3.0.0

Compare Source

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Breaking changes:

• Drop Node.js 4 & 6 support
• Add Node.js 10 & 12 support
• Upgrade mongoose to v5 and mongodb to v3 and drop old version support
• Replace deprecated mongo operation
• MongoStore need to supply client/clientPromise instead of db/dbPromise due to depns upgrade

Others changes:

• Add Implement store.all function (#​291)
• Add Add option writeOperationOptions (#​295)
• Add Transparent crypto support (#​314)
• Change test framework from Mocha to Jest
• Change linter from xo to eslint

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