Error in flow_to_exit

[saraedum]

Here, the flow is computed incorrectly. We are flowing in direction (0, 1) so we should not be able to go from (2, 1) to (2, 0).

sage: from flatsurf import Polygon
sage: P = Polygon(vertices=[(1, 0), (1, -2), (3/2, -5/2), (2, -2), (2, 0), (2, 1), (2, 3), (3/2, 7/2), (1, 3), (1, 1)])
sage: P.flow_to_exit(vector((2, 1)), vector((0, 1)))
((2, 0), point positioned on vertex 4 of polygon)
# should be: ((2, 3), point positioned on vertex 6 of polygon)

[saraedum]

Fixed in #211.