fix: Set base URI when storing summary (#70)

Fix error `Unable to resolve URIs, no base URI has been set` when
storing summaries, caused by #66, which introduced relative URIs 
for classPartitions.

src/graphdb.ts

@@ -32,7 +32,11 @@ export class GraphDBClient implements WriterSparqlClient, ImporterSparqlClient {
 
  async store(dataset: Dataset, summary: DatasetCore): Promise<void> {
  try {
- await this.repository.putQuads([...summary], dataset.iri);
+ await this.repository.putQuads(
+ [...summary],
+ dataset.iri,
+ `<${dataset.iri}>`
+ );
  } catch (e) {
  console.error(
  'Write to GraphDB failed for dataset ' + dataset.iri,