https://travis-ci.org/preesm/graphiti/builds/551545973 is helpful, you should be able to replicate it locally by the following in your ~/.m2/settings.xml file:
<mirrors>
<mirror>
<id>google-maven-central</id>
<name>Google Maven Central</name>
<url>https://storage-download.googleapis.com/maven-central/repos/central/data/</url>
<mirrorOf>central</mirrorOf>
</mirror>
</mirrors>
I’ll look into the missing files – if that’s all it is, I should be able to fix in an hour or two, but figuring out why might take longer. Will update the issue in 30 min.