Opus CAPES added
@lhoestq I saw some common changes you made on the other PR's (Similar Opus Datasets). I fixed those changes here. Can you please review it once ? 
Thanks. Hi @rkc007 , thanks for the contribution.
Unfortunately, the CAPES dataset has already been added here: #1307
I'm closing the PR  @lhoestq FYI
Dataset : http://opus.nlpl.eu/CAPES.php