Added RONEC dataset.
Thanks for the PR @iliemihai . 

Few comments - 

Can you run - 
`python datasets-cli dummy_data ./datasets/ronec --auto_generate` to generate dummy data.

Also, before committing files run : 
`make style`
`flake8 datasets`
then you can add and commit files. > Thanks for the PR @iliemihai .
> 
> Few comments -
> 
> Can you run -
> `python datasets-cli dummy_data ./datasets/ronec --auto_generate` to generate dummy data.
> 
> Also, before committing files run :
> `make style`
> `flake8 datasets`
> then you can add and commit files.

Sorry, forgot to generate dummy data. I will do it now :D Awesome, good job @iliemihai !
I think the PR is ready to merge.
@lhoestq would you mind double-checking this ? Had to regenerate the dummy data since I just found out they were empty files