routing: add new vertex and to new channels to basic_graph.json
routing: add new vertex and to new channels to basic_graph.json

In this commit, we add a new node to the current default test graph
that we use for our path finding tests. This new node connects roasbeef
to sophon via a new route with very high fees. With this new node and
the two channels it adds, we can properly test that we’ll route around
failures that we run into during payment routing.

aakselrod/lnd,aakselrod/lnd,LightningNetwork/lnd,LightningNetwork/lnd