First commit for GA4GH common classes and Picard runner

About that service path: 
It works when I do this:
GenomicsFactory genomicsFactory = GenomicsFactory
              .builder("genomics_java_client")
              .setScopes(SCOPES)
              .setRootUrl(rootUrl)
              .setServicePath("/")
              .setVerificationCodeReceiver(Suppliers.ofInstance(receiver))
              .build();
      return genomicsFactory.fromClientSecretsFile(clientSecrets);

... but not when I do this
GenomicsFactory genomicsFactory = GenomicsFactory
              .builder("genomics_java_client")
              .setScopes(SCOPES)
              .setRootUrl(rootUrl)
              .setVerificationCodeReceiver(Suppliers.ofInstance(receiver))
              .build();
      return genomicsFactory.fromClientSecretsFile(clientSecrets);

So it looks like for accessing Genomics API on Google setServicePath("/") IS needed (or maybe I completely missed the gist of your comment).