poly2tri includes JUNIT dependencies at compile scope

[robabod]

As reported on the h2gis project, it appears that the current version of poly2tri includes a JUNIT dependency at compile scope.

As per the latest pom.xml:

<dependency>
  <groupId>org.junit.jupiter</groupId>
  <artifactId>junit-jupiter-api</artifactId>
  <version>${junit-version}</version>
</dependency>