IBM JSON4J ClassNotFound when running unit test

I am developing a basic servlet deployed on WebSphere Liberty. This servlet uses a custom class I wrote to perform its business logic.

I tried to write some unit tests for this custom class which I can run using maven. But when I launch maven test, some tests fail with the following exception:

java.lang.NoClassDefFoundError: com/ibm/json/java/internal/SerializerVerbose
at com.ibm.utils.JMAuthorizationModule.processPostRequest(JMAuthorizationModule.java:78)
at com.ibm.test.JMAuthorizationModuleTest.shouldNotAcceptToCreateASkillForADifferentUser(JMAuthorizationModuleTest.java:42)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:252)
at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:141)
at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:112)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:189)
at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:165)
at org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:85)
at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:115)
at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:75)
Caused by: java.lang.ClassNotFoundException: com.ibm.json.java.internal.SerializerVerbose
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 32 more

The class that I intend to test uses the IBM Library JSON4J. The class can run without any problem when my servlet is deployed inside the Liberty runtime, but apparently the JSON4J is not found by maven when the tests are run.

Could you please explain what I should configure so that the ClassNotFound is not thrown when running my tests?

I also attach my pom.xml in case it may help:

<project xmlns="http://ift.tt/IH78KX" xmlns:xsi="http://ift.tt/ra1lAU"
xsi:schemaLocation="http://ift.tt/IH78KX http://ift.tt/VE5zRx">

<repositories>
    <repository>
        <id>maven online</id>
        <name>maven repository</name>
        <url>http://ift.tt/1Suicfc;
    </repository>
    <repository>
        <id>liberty maven online</id>
        <name>liberty maven repository</name>
        <url>http://ift.tt/1rmldQx;
    </repository>
</repositories>

<modelVersion>4.0.0</modelVersion>
<groupId>com.ibm.jm.tests</groupId>
<artifactId>TestSecurityGateway</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<name>Test</name>

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.apache.geronimo.specs</groupId>
            <artifactId>geronimo-servlet_3.0_spec</artifactId>
            <version>1.0</version>
        </dependency>
    </dependencies>
</dependencyManagement>

<dependencies>
    <dependency>
        <groupId>com.ibm.tools.target</groupId>
        <artifactId>was-liberty</artifactId>
        <version>LATEST</version>
        <type>pom</type>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.apache.geronimo.specs</groupId>
        <artifactId>geronimo-servlet_3.0_spec</artifactId>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.5.2</version>
    </dependency>
    <dependency>
        <groupId>org.jsoup</groupId>
        <artifactId>jsoup</artifactId>
        <version>1.9.2</version>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
        <scope>test</scope>
    </dependency>
</dependencies>

<build>
    <pluginManagement>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.5.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <configuration>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                    <warName>JMTestApp</warName>
                    <outputDirectory>bluemix/apps</outputDirectory>
                </configuration>
            </plugin>
        </plugins>
    </pluginManagement>
</build>

Thanks