This is message I received from jcenter:
JCenter hosts Java applications that follow the Maven convention. In addition to the .aar file, your version should include a pom file, a *-sources.jar, and optionally a *-javadoc.jar. Your files should be under a Maven path layout. (see https://bintray.com/docs/usermanual/uploads/uploads_includingyourpackagesinjcenter.html)
This is my project which I try to upload to jcenter:
https://dl.bintray.com/leaking/maven/com/quinn/hunter/hunter-linelog-plugin/0.8.5/
