I see... so final advice: revert back to the original pom.xml and change slf4j version from 1.5.10 to 1.6.1 like this:
<org.slf4j-version>1.6.1</org.slf4j-version>
Actually I've tested it myself on weblogic 12c. The problem is that slf4j is bundled in weblogic and the version bundled is 1.6.1 and it conflicts with 1.5.10. Hope this helps get you started.

