Changes

update for next development version
 (commit: 3fd857e)

- Filtering on subject values
- Projection of subject variables
- Add support for RDF data (NTriples)
- Remove requiring the projection of the filtered object
- Running queries with only one relevant data source
- Add query-time transformations
- Change the timer to count the full execution time instead of only Spark execution time
- Improve exception handling and logging messages
- Change query results format, from `show()` method to `foreach(println)` method
 (commit: b91e449)

- Add RDF connector source files
 (commit: 80badae)

- Remove extra argument
 (commit: 07aeb2e)

- Change the version to 0.1.2 from a SNAPSHOT
 (commit: 85e5c2c)

- Change the version to 0.1.2 from a SNAPSHOT in parent
 (commit: 84ffde8)

- Change the version back to 0.1.2 SNAPSHOT
 (commit: 15084cf)

- clean and organize imports
- use spark version 2.4.4
- delete unnecessary dependencies in pom
 (commit: 434ad6f)

Remove properties and add sansa-parent as parent
 (commit: 4a70583)

update versions for release
 (commit: 17fd012)