Ward reduction test

[jd-lara]

This test seems to be incorrectly set up so it broke with a small change to the kwarg passing

#TODO - develop more robust testing for correctness of PTDF
@testset "Test similarity of PTDF with Ward" begin
    sys = PSB.build_system(PSB.PSIDSystems, "3 Bus Inverter Base")
    ptdf_3 = PTDF(sys)
    ptdf_2 = PTDF(sys; network_reductions = NetworkReduction[WardReduction([101, 102])])
    @test abs(ptdf_3["BUS 1-BUS 2-i_1", 102] - ptdf_2["BUS 1-BUS 2-i_1", 102]) < 0.0025
end

it is commented out in the PSY5 branch

[jd-lara]

The code also needs testing for LODF using ward decomposition