feat(locators): remove deprecated locator APIs

This is a **breaking change**. The following deprecated Locator APIs have been
removed.

- `by.input`
- `by.select`
- `by.selectedOption`
- `by.textarea`

`input`, `select`, and `textarea` can be replaced by `by.model`.

`element(by.selectedOption('foo'))` can be replaced by `element(by.model('foo')).$('option:checked')`