Use maven-enforcer-plugin instead of prerequisites in archetypes

[Aleksey Shipilev]

Hey,

On 04/12/2017 07:47 PM, Christoph Dreis wrote:
> as of Maven 3.5 using <prerequisites>..</prerequisites> for a non
> maven-plugin project, will output a warning in the console.

Thanks for the heads-up. Fixed as:
  https://bugs.openjdk.java.net/browse/CODETOOLS-7901948

-Aleksey