Add Google Drive and Dropbox as Places in Office 2016

Normally Sharepoint and OneDrive are the only Cloud providers visible in Office 2016. To add Dropbox and Google Drive follow the following instructions:

For Dropbox:
Install the Dropbox client for Windows.
Click the system tray icon, and choose preferences, “Show Dropbox as a place”
Restart Office.

For Google Drive:
Download a plugin from here.
Install it.