[XGLUE] Adding new dataset
Okey actually not that easy to add things like `test-de` to `datasets` => this would be the first dataset to have this.
See: https://github.com/huggingface/datasets/pull/802
XGLUE is a multilingual GLUE like dataset propesed in this [paper](https://arxiv.org/pdf/2004.01401.pdf).

I'm planning on adding the dataset to the library myself in a couple of weeks.
Also tagging @JetRunner @qiweizhen in case I need some guidance 
[XGLUE] Adding new dataset 
 XGLUE is a multilingual GLUE like dataset propesed in this [paper](https://arxiv.org/pdf/2004.01401.pdf).

I'm planning on adding the dataset to the library myself in a couple of weeks.
Also tagging @JetRunner @qiweizhen in case I need some guidance  
 Okey actually not that easy to add things like `test-de` to `datasets` => this would be the first dataset to have this.
See: https://github.com/huggingface/datasets/pull/802