Loading GLUE dataset loads CoLA by default
Yes so the first config is loaded by default when no `name` is supplied but for GLUE this should probably throw an error indeed.

We can probably just add an `__init__` at the top of the `class Glue(nlp.GeneratorBasedBuilder)` in the `glue.py` script which does this check:
```
class Glue(nlp.GeneratorBasedBuilder):
    def __init__(self, *args, **kwargs):
        assert 'name' in kwargs and kwargs[name] is not None, "Glue has to be called with a configuration name"
        super(Glue, self).__init__(*args, **kwargs)
```
If I run:

```python
dataset = nlp.load_dataset('glue')
```
The resultant dataset seems to be CoLA be default, without throwing any error. This is in contrast to calling:

```python
metric = nlp.load_metric("glue")
```
which throws an error telling the user that they need to specify a task in GLUE. Should the same apply for loading datasets?
Loading GLUE dataset loads CoLA by default 
 If I run:

```python
dataset = nlp.load_dataset('glue')
```
The resultant dataset seems to be CoLA be default, without throwing any error. This is in contrast to calling:

```python
metric = nlp.load_metric("glue")
```
which throws an error telling the user that they need to specify a task in GLUE. Should the same apply for loading datasets? 
 Yes so the first config is loaded by default when no `name` is supplied but for GLUE this should probably throw an error indeed.

We can probably just add an `__init__` at the top of the `class Glue(nlp.GeneratorBasedBuilder)` in the `glue.py` script which does this check:
```
class Glue(nlp.GeneratorBasedBuilder):
    def __init__(self, *args, **kwargs):
        assert 'name' in kwargs and kwargs[name] is not None, "Glue has to be called with a configuration name"
        super(Glue, self).__init__(*args, **kwargs)
```