Specify version of maven-exec plugin
<artifactId>maven-clean-plugin</artifactId>
<version>3.0.0</version>
</plugin>
+ <plugin>
+ <groupId>org.codehaus.mojo</groupId>
+ <artifactId>exec-maven-plugin</artifactId>
+ <version>1.6.0</version>
+ </plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-install-plugin</artifactId>
