Fixed test_network:TestNetwork.test_aspydot(). The underlying pydot library changed its interface slightly.
Fixed test_network:TestNetwork.test_aspydot(). The underlying pydot library changed its interface slightly.

git-svn-id: e6d44ec3d56a4b51a9cad284a9139aeaee5a4315@95 3447e8dd-9f38-0410-a211-e3037a7e05e3

arnaudsj/pebl,arnaudsj/pebl,arnaudsj/pebl