Storage integration with Google Drive and/or Dropbox

Integration with Google cloud storage is a long requested feature in Rocket.Chat. This project aims to integrate Google Drive and Dropbox storage with Rocket.Chat, thereby allowing users to authorize Rocket.Chat to access their Drive/Dropbox accounts in exchange for a bunch of features. These include (i) upload content to Drive/Dropbox accounts directly from Rocket.Chat, (ii) create Google docs, slides and spreadsheets in Rocket.Chat for enhanced real-time collaboration, (iii) browse and download Drive/Dropbox content from Rocket.Chat using GUIs that respective APIs provide, (iv) supporting features such as file preview for Drive content and finally, rigorous tests for the project implementation.