Investigate if it is possible to run igraph from scala

[smacker]

igraph is a C library. There is some experimental binding to java exist. But maybe we can build our own because we need only very small subset of igraph.

Problems with current approach:

• we add python dependency only to call igraph
• it requires correct environment or scala part would fail
• extra code that serialize/unserialize data to exchange between scala&python
• it's difficult to debug