Add hint to the guide to include 'bintary jcenter' into pom.xml in tag repository

[Naoghuman]

Hi Andreas,

like I said in twitter I was a little confuse as I tried to inject the library through maven central in my maven project. With your help I was able to fix my pom with:

<repositories>
  <repository>
    <id>central</id>
    <name>bintray</name>
    <url>http://jcenter.bintray.com</url>
  </repository>
</repositories>

As I see you have a fantastic guide for your project, so I think it would be a good idea to extend the guide about this informations. What do you mean?

Greetings
Peter