Fastcore

New Features

- Remove numpy prerequisite ([75](https://github.com/fastai/fastcore/issues/75))
- NB: fastcore's `L` and other collection features still work with numpy
arrays, but they do so internally using instance methods, so numpy is no longer a
prerequisite, and numpy is not loaded if not used

Bugs Squashed

- "has default params. These will be ignored" shown when not appropriate ([74](https://github.com/fastai/fastcore/issues/74))

Breaking Changes

- Change arguments of `store_attr()` and remove `store_attrs` attribute ([71](https://github.com/fastai/fastcore/pull/71))
- `store_attr`'s API has changed. `self` is now the second parameter, and is optional. Previously, if no names were passed to store,
names were taken from the `store_attrs` attribute; now, however, names are taken from the list of arguments to the current function.

New Features

- Warn if defaults passed to `typedispatch` ([73](https://github.com/fastai/fastcore/pull/73))

- Add `urlread` and `urljson` ([72](https://github.com/fastai/fastcore/pull/72))

- Initial release