Allows community/enterprise users installing ezplatform / ezplatform-demo to get the latest version. In the current state, they need to run composer update at least once to get the updates.

Updated packages (to be updated if needed):

• platform-ui-bundle v1.2.1
• ezpublish-kernel v1.2.1

Deliverables

• v1.2.1 tag of ezsystems/ezplatform
  should not incorporate any changes other than the lock update.
• v1.2.1 tag of ezplatform-demo

In both cases, only updates to our own packages should be in the lock (to restrict changes and limit the need for thorough QA).

Questions

• about release notes, I suggest we just update the packages numbers on the 16.02 page
• if we need to name it, do we use "16.02.1" ? Given that this is not a tag, we don't have to follow a x.y.z scheme. It's a lightweight update, in any case.