Maven build failure for jsonld-java

[MatthiasHinz]

Hi,
I tried out the metadata-extractor and finally succeeded to set it up, but at first try I had the following build failure after running mvn install:

[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  18.591 s
[INFO] Finished at: 2019-07-03T14:00:42Z
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal on project opal-metadata-extraction: Could not resolve dependencies for project org.dice-research:opal-metadata-extraction:war:1.0.0-SNAPSHOT: Could not find artifact com.github.jsonld-java.jsonld-java:jsonld-java:bundle:0.12.1 in jitpack.io (https://jitpack.io) -> [Help 1]

I solved this by adding the jsonld-java dependency to the pom.xml, as descriped here:
https://github.com/jsonld-java/jsonld-java