Migrate to Maven Central

[GuilhE]

JFrog just announced that they'll be shutting down JCenter: https://jfrog.com/blog/into-the-sunset-bintray-jcenter-gocenter-and-chartcenter/

Key dates are:

• February 28th: No more submissions will be accepted to Bintray, JCenter
• May 1st: Bintray, JCenter services will no longer be available

Hence, ImagePicker should also be migrated to another maven repository like Maven central. Since you have all files needed for Maven, here's a quick Migrating old artifacts from JCenter to MavenCentral guide

ps: Yes, this repo is available on jitpack but with the above guide you could also add it to MavenCentral easily.