Add tests for `_.map`, `_.invoke`, `_.shuffle`, and `_.sortBy` for treating numbers as empty.
Update link to curry post in readme. [ci skip]
Merge branch 'master' of github.com:lodash/lodash
Merge branch 'master' of github.com:lodash/lodash
Ensure sparse arrays are treated as dense by `_.keys` and `_.keysIn` and ensure support for string objects in `_.keys` and `_.keysIn`.
Rebuild dist.