Add support for sbt with sbt-dependency-graph

[rtfpessoa]

Add support for https://github.com/jrudolph/sbt-dependency-graph to read Scala projects dependencies.

Suggestions:

• Help user setup sbt-dependency-graph
• Execute sbt-dependency-graph and retrieve the dependencies like we do with bibliothecary for the others.
• Analyse the dependencies like the other sources
• Create some tests