Tapas v4 (tres)
Here we are again, opening a new PR based on the former (#8988) which had some Github issues. 
cc @LysandreJik 
Don't worry about the TF tests, these are because of TF2.4 which are fixed on `master`.<|||||>The conversion script currently includes a line in which I'm importing a local `vocab.txt`, I know this should be removed in the future.