Fails to load in Pharo 9

[sebastianconcept]

It's a consequence of a dependency of PythonBridge failing to load OSSubprocess in Pharo 9.

I've loaded using this in BaselineOfKerasBridge

baseline: spec
	<baseline>
	spec
		for: #common
		do: [
			spec baseline: 'NeoJSON' with: [
                spec repository: 'github://svenvc/NeoJSON/repository' ].
			spec baseline: 'PythonBridge' with: [
                spec repository: 'github://sebastianconcept/PythonBridge:v0.1.1/src' ].

I've left this PR if that helps ObjectProfile/PythonBridge#12