Licensing incompatibility with peer dependency immutable-js

Do you want to request a feature or report a bug? Licensing issue

What is the current behavior? Draft-js is released under MIT, but it only works together with immutable-js ~3.7.4, which is licensed under the old BSD + Patents license. Since npm/yarn will install version 3.7.6, we must force the use of immutable-js 3.8.2 or higher to avoid any licensing issues. This might not be apparent to everyone.

See also #1425.