plotBipartiteGraph: use_edge_attributes doesnt work with newest igraph version

[KarinSchork]

The newest igraph version 2.2.0 causes an error in the test when use_edge_attributes (maybe only when no edge was deleted, but I'm not sure). I disabled this for now to make the tests work but we should fix that later.

[KarinSchork]

Also, the diamond shape does not seem to work at the moment for some reason (maybe also beause of the new igraph version?)

[KarinSchork]

When fixed, we should also set igraph 2.2.0 as a minimum version in the DESCRIPTION file

[KarinSchork]

diamond shape works now again, but the plot is know smaller / borders are larger?

[KarinSchork]

There is no "deleted" attribute when deleting an edge or vertex, maybe it was in a former igraph version? Do we still need that option? Anyway, te name "use_edge_attributes" is maybe not fitting too well.