Issue generating Pact files using PactContractConverter - pact

Question

I'm trying to generate the pact files as specified here so I can verify the results to my broker.
Version: spring cloud 2.2.2 & Pact JVM 3.5.23.
I've configured the plugin as shown below...
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<version>1.6.0</version>
<executions>
<execution>
<id>convert-dsl-to-pact</id>
<phase>process-test-classes</phase>
<configuration>
<classpathScope>test</classpathScope>
<mainClass>org.springframework.cloud.contract.verifier.util.ToFileContractsTransformer</mainClass>
<arguments>
<argument>org.springframework.cloud.contract.verifier.spec.pact.PactContractConverter</argument>
<argument>${project.basedir}/target/pacts</argument>
<argument>${project.basedir}/target/generated-test-sources/contracts</argument>
</arguments>
</configuration>
<goals>
<goal>java</goal>
</goals>
</execution>
</executions>
</plugin>
I get the following error...
[INFO] --- exec-maven-plugin:1.6.0:java (convert-dsl-to-pact) # employee ---
...
10:55:24.349 [org.springframework.cloud.contract.verifier.util.ToFileContractsTransformer.main()] WARN org.springframework.cloud.contract.verifier.util.ContractVerifierDslConverter - Exception occurred while trying to parse the file [/Users/luke/workspaces/dbs/employee/employee-service/employee/target/generated-test-sources/contracts/com/backbase/dbs/employee/contract/com/backbase/dbs/employee/employee_serviceagreements_get_api_producer_pact/ContractsTest.java] as a contract. Will not parse it.
java.lang.IllegalStateException: Class with name [ContractsTest] not found
at org.springframework.cloud.contract.verifier.util.ContractVerifierDslConverter.classConstructor(ContractVerifierDslConverter.groovy:166)
at org.springframework.cloud.contract.verifier.util.ContractVerifierDslConverter.parseJavaFile(ContractVerifierDslConverter.groovy:144)
at org.springframework.cloud.contract.verifier.util.ContractVerifierDslConverter.toObject(ContractVerifierDslConverter.groovy:131)
at org.springframework.cloud.contract.verifier.util.ContractVerifierDslConverter.convertAsCollection(ContractVerifierDslConverter.groovy:98)
at org.springframework.cloud.contract.verifier.util.ContractScanner$1.visitFile(ContractScanner.groovy:88)
at org.springframework.cloud.contract.verifier.util.ContractScanner$1.visitFile(ContractScanner.groovy)
at java.nio.file.Files.walkFileTree(Files.java:2670)
at java.nio.file.Files.walkFileTree(Files.java:2742)
at org.springframework.cloud.contract.verifier.util.ContractScanner.collectContractDescriptors(ContractScanner.groovy:77)
at org.springframework.cloud.contract.verifier.util.ContractScanner.collectContractDescriptors(ContractScanner.groovy:59)
at org.springframework.cloud.contract.verifier.util.ToFileContractsTransformer.storeContractsAsFiles(ToFileContractsTransformer.groovy:75)
at org.springframework.cloud.contract.verifier.util.ToFileContractsTransformer.main(ToFileContractsTransformer.groovy:55)
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.codehaus.mojo.exec.ExecJavaMojo$1.run(ExecJavaMojo.java:282)
at java.lang.Thread.run(Thread.java:748)
The generated sources and generated tests seem to be in the correct place.
Any ideas?