I have the same error.
In the /target folder I have the following 4 jars:
osm-0.2.3-neo4j-4.0.9-javadoc.jar
osm-0.2.3-neo4j-4.0.0-sources.jar
osm-0.2.3-neo4j-4.0.0-procedures.jar
osm-0.2.3-neo4j-4.0.0.jar
I see a OSMImportTool.class at osm/target/cla...
