Hey Jules, seems you forgot to add juce_amalgamated_template.mm to the repository. Cheers.
…are you the antiorp?
There isn’t supposed to be a .mm template file! Because you don’t need one - just include juce_amalgamated_template.cpp in you own .mm file and it’ll work just the same.
Well, I use the template file to build the library (I’m using a qmake project file, so this saves a lot of trouble). So I do need the .mm. It’s no big problem to add one myself ofcoarse, just thought I’d mention it for completeness.
… and I’m not the antiorp 
In my projects I never use the amalgamated files directly, because you’re likely to want to set some app-specific config flags, and to do that you need to include it from your own custom file - I think the way it’s done in the demos with a JuceSource.mm file works pretty well.
I use project defines for this, works perfectly well. The amalgamated template file is ideal to build the library in another project form than the ones provided (such as qmake).