IQN is broken with Julia@v1.6

[findmyway]

Seems to be caused by JuliaLang/julia#37829

Before:

julia> CartesianIndices((0, 0:7, 0))
1×8×1 CartesianIndices{3,Tuple{UnitRange{Int64},UnitRange{Int64},UnitRange{Int64}}}:
[:, :, 1] =
 CartesianIndex(0, 0, 0)  …  CartesianIndex(0, 7, 0)

Now:

julia> CartesianIndices((0, 0:7, 0))
0×8×0 CartesianIndices{3, Tuple{Base.OneTo{Int64}, UnitRange{Int64}, Base.OneTo{Int64}}}

[pilgrimygy]

In fact, the PPO experiment on 'pong' has similar problems, please check it.

[findmyway]

In fact, the PPO experiment on 'pong' has similar problems, please check it.

I'll take a look into it.