Merge pull request #59 from etsiinf/master

Adding RDFs
Sergio Conde: Added graph to ttl exercise.
Sergio Conde: Added graph to xmlrdf exercise.
Sergio Conde: Added xmlrdf to graph exercise.
Sergio Conde: Fix indent...
Merge pull request #60 from skgsergio/master

Sergio Conde: Exercises from assignment 2.
Update DatasetDescriptions.csv
Create Daniel_Sanchez_Rodriguez_RDF
Merge pull request #62 from asenjus/patch-1

Update DatasetDescriptions.csv
Merge pull request #67 from DanielSanchezRodriguez/patch-3

Create Daniel_Sanchez_Rodriguez_RDF
Merge remote-tracking branch 'upstream/master'