Updated packages required and fixed bugs created by updating package versions

[sammyhass]

Updated import statements to reflect updated api and updated readme to show process of getting client_secret.json

When I tested the master branch prior to this commit, it would throw constant errors regarding missing packages, I have now fixed these errors by adding the packages back. They must've been removed in a previous commit that I glossed over.

@stewartmcgown if you don't mind just checking everything is okay here then we should be good to merge.