Package 3rd party jar and .so dependency with Maven - maven

Question

We use a third party jar which is essentially an entrypoint to method definitions provided by two dynamically linked libraries (.so). We want to include these in a maven build. The third party jar is easy, but how do we include the libraries, as without them we're getting a linker error at runtime?
sqlrelay is the third party dependency, which was installed with the following command:
mvn install:install-file -Dfile=sqlrelay.jar -DgroupId=com.firstworks -DartifactId=sqlrelay -Dpackaging=jar -Dversion=1.2.1
the runtime error is:
java.lang.UnsatisfiedLinkError no SQLRConnection in java.library.path
This is a Spring Boot application, here's my pom:
http://maven.apache.org/xsd/maven-4.0.0.xsd">
4.0.0
<groupId>org.springframework</groupId>
<artifactId>gs-rest-service</artifactId>
<version>0.1.0</version>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.9.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.jayway.jsonpath</groupId>
<artifactId>json-path</artifactId>
<scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/com.amazonaws/aws-java-sdk-s3 -->
<dependency>
<groupId>com.amazonaws</groupId>
<artifactId>aws-java-sdk-s3</artifactId>
<version>1.11.248</version>
</dependency>
<dependency>
<groupId>com.firstworks</groupId>
<artifactId>sqlrelay</artifactId> >
<version>1.2.1</version>
</dependency>
<dependency>
<groupId>com.bettercloud</groupId>
<artifactId>vault-java-driver</artifactId>
<version>3.0.0</version>
</dependency>
</dependencies>
<properties>
<java.version>1.8</java.version>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
<repositories>
<repository>
<id>spring-releases</id>
<url>https://repo.spring.io/libs-release</url>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>spring-releases</id>
<url>https://repo.spring.io/libs-release</url>
</pluginRepository>
</pluginRepositories> </project>
mvn clean install
builds without error and the application runs. The problem is only hit when an endpoint references the library in question.
Thanks
S