Trouble creating a fat jar in gradle - Using Eclipse IDE, Kryonet and LibGDX

Question

Currently I am designing an online multiplayer game for a university project using Eclipse IDE and using libraries Kryonet and LibGDX.

I'm having trouble creating a fat jar in gradle, I've followed tutorials and applied the code into my build.gradle however nothing has worked.

Any help or advice is much appreciated!

My .classpath file

<?xml version="1.0" encoding="UTF-8"?>
<classpath>
    <classpathentry kind="src" output="bin/main" path="src">
        <attributes>
            <attribute name="gradle_scope" value="main"/>
            <attribute name="gradle_used_by_scope" value="main,test"/>
        </attributes>
    </classpathentry>
    <classpathentry kind="src" output="bin/main" path="assets">
        <attributes>
            <attribute name="gradle_scope" value="main"/>
            <attribute name="gradle_used_by_scope" value="main,test"/>
        </attributes>
    </classpathentry>
    <classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.7/">
        <attributes>
            <attribute name="module" value="true"/>
        </attributes>
    </classpathentry>
    <classpathentry kind="con" path="org.eclipse.buildship.core.gradleclasspathcontainer"/>
    <classpathentry kind="lib" path="C:/Users/44756/Documents/University/Year 2/Term 2/Team Project/GameTerm2/rooster-run-main-main/kryonet-2.21-all.jar"/>
    <classpathentry kind="output" path="bin/default"/>
</classpath>