Importing local Python module fails in Julia 1.4?

Hi, I have the following code
```julia
using PyCall
pushfirst!(PyVector(pyimport("sys")."path"), srcdir())
pypsd = pyimport("PSD")
```
`srcdir()` is a *directory* that points to a *folder* which includes a *file* `PSD.jl`.I was using this code about 3 months ago and it worked fine for me.

Unfortunately it doesn't work anymore, even though there was absolutely nothing changed in my source code:
```
ERROR: LoadError: PyCall.PyError("PyImport_ImportModule\n\nThe Python package PSD could not be found by pyimport. Usually this means\nthat you did not install PSD in the Python version being u...
```

The only difference with the past I can think of is that I'm now using a more recent Julia version, 1.4. Has the way of including local modules changed? I've looked at the readme, but I only found a note that PyCall.jl doesn't include current directory by default, but this is not my case.

Reproduisez l’échec avec la séquence indiquée de `PyCall`, `pyimport("sys")`, `sys.path`, `srcdir()` et `PSD` sous Julia 1.4. Commencez par vérifier comment le répertoire local et le module `PSD` sont exposés à Python, puis comparez le comportement avec la configuration qui fonctionnait auparavant. Le travail est terminé lorsque le module local `PSD` s’importe correctement ou que le problème est clarifié avec la configuration requise.

Rédigé par le modèle d'indexation à partir du texte de l'issue.