Build failed bc compile fileTree(dir: 'libs', include: ['*.jar'])

[11510746]

travis-ci build failed since it didn’t load the local jar. How to resolve it ?

My travis file

language: java
jdk: oraclejdk8

My gradle file

apply plugin: 'java'
sourceCompatibility = 1.8

repositories {
    mavenCentral()
}

dependencies{

    compile "fr.inria.gforge.spoon:spoon-core:7.3.0"
    compile group: 'commons-io', name: 'commons-io', version: '2.5'
    compile group: 'com.google.guava', name: 'guava', version: '19.0'
    compile "fr.inria.gforge.spoon.labs:gumtree-spoon-ast-diff:1.8"
    compile group: 'org.apache.commons', name: 'commons-math3', version: '3.6.1'
    compile group: 'junit', name: 'junit', version: '4.12'

    // Include the jar by "mvn package" on https://github.com/hammadirshad/InMemoryJavaCompiler
    // This is a substitute for the following:
    // compile "org.mdkt.compiler:InMemoryJavaCompiler:1.3.0"
    // ... because InMemoryJavaCompiler has yet to incorporate the critical bugfix
    compile fileTree(dir: 'libs', include: ['*.jar'])
}

travis-ci build result