Add newaxis to torch aliases

Closes gh-64

Author: rgommers

Diff for: array_api_compat/torch/_aliases.py

@@ -144,6 +144,7 @@ def can_cast(from_: Union[Dtype, array], to: Dtype, /) -> bool:
 
 # Basic renames
 bitwise_invert = torch.bitwise_not
+newaxis = None
 
 # Two-arg elementwise functions
 # These require a wrapper to do the correct type promotion on 0-D tensors
@@ -694,7 +695,7 @@ def take(x: array, indices: array, /, *, axis: Optional[int] = None, **kwargs) -
            'atan2', 'bitwise_and', 'bitwise_left_shift', 'bitwise_or',
            'bitwise_right_shift', 'bitwise_xor', 'divide', 'equal',
            'floor_divide', 'greater', 'greater_equal', 'less', 'less_equal',
-           'logaddexp', 'multiply', 'not_equal', 'pow', 'remainder',
+           'logaddexp', 'multiply', 'newaxis', 'not_equal', 'pow', 'remainder',
            'subtract', 'max', 'min', 'sort', 'prod', 'sum', 'any', 'all',
            'mean', 'std', 'var', 'concat', 'squeeze', 'broadcast_to', 'flip', 'roll',
            'nonzero', 'where', 'reshape', 'arange', 'eye', 'linspace', 'full',