added a couple of features in travis yml
first draft of ResourceTreeItem
tests for the RDFTreeItem, first draft
Merge pull request #8 from asobolev/master

First draft of TreeItem for RDF navigation as a tree

LGTM, thanks
Merge pull request #9 from stoewer/master

Project config dialog
using built-in RDF terms
draft of the metadata service
removed metadata path methods from the project config
Merge pull request #10 from asobolev/master

Draft of the metadata service