Package Update issues

[allanice001]

W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://dl.yarnpkg.com/debian stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 23E7166788B63E1E
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.2 Release: The following signatures were invalid: KEYEXPIRED 1507497109
W: Failed to fetch https://dl.yarnpkg.com/debian/dists/stable/InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 23E7166788B63E1E
W: Failed to fetch http://repo.mongodb.org/apt/ubuntu/dists/xenial/mongodb-org/3.2/Release.gpg The following signatures were invalid: KEYEXPIRED 1507497109
W: Some index files failed to download. They have been ignored, or old ones used instead.
v

[allanice001]

Fix for Yarn: yarnpkg/yarn#4453

wget -qO - https://raw.githubusercontent.com/yarnpkg/releases/gh-pages/debian/pubkey.gpg | sudo apt-key add -

[allanice001]

Fix for Mongo:
MongoDB Current Stable Release is now (4.0.x).
(Steps taken from https://docs.mongodb.com/manual/tutorial/install-mongodb-on-ubuntu/)

sudo rm /etc/apt/sources.list.d/mongodb*.list
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 9DA31620334BD75D9DCB49F368818C72E52529D4
echo "deb [ arch=amd64,arm64 ] https://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/4.0 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-4.0.list
sudo apt update