Potential bug in /sharpy/aero/modals/aerogrid.py

[LeeElvis]

Describe the bug
In lines 273, 280 and 313, according to the Aerodynamics input h5file: I think that the control surface info ['control_surface_hinge_coords'] should be ['control_surface_hinge_coord'].
Thank you.

[ACea15]

Nicely spot Lee, you could still run your model with 'control_surface_hinge_coords' if you put it in the input h5-file, but indeed in the docs it is 'control_surface_hinge_coord' and doing a -grep shows inputs in the examples are without the 's'.
Totally looks like a refactoring that missed that line, what is more worrying is that none of the tests picked that up.
Will fix it, thanks.