removed credentials: "include" by default.
Supply your own CookieAuthenticator to handle cookies on cross domain.

Even if it is a private package,
a license is usefull,
because code may be copied and pasted.
We used LGPLv3+ because it is used in other packages,
so like this it is the same for all packages,
but we may use a non-copyleft license for this specific package,
like Creative Commons 0 version 1.0
(https://www.gnu.org/licenses/license-list.en.html#CC0)
or GNU All-Permissive License
(https://www.gnu.org/licenses/license-list.en.html#GNUAllPermissive).

It is already the license that is used:

```
$ grep -r --include=package.json license | grep -v node_module
packages/data-provider/package.json:  "license": "LGPL-3.0-or-later",
packages/rql-generator/package.json:  "license": "LGPL-3.0-or-later",
packages/client/package.json:  "license": "LGPL-3.0-or-later",
packages/react-form-utils/package.json:  "license": "LGPL-3.0-or-later",
packages/yup/package.json:  "license": "LGPL-3.0-or-later",
```