spec: move project saving to within the copy function.

[ashdnazg]

This prevents the mistake where a test doesn't do anything because we
forgot to call the save function.

[barakwei]

This feels a bit weird. The thing is that you're using cp to copy the file, so you have to save the file before copying. Now that you pass the project, you can probably just project.save(new_path) and you'll have all the new state in the project.
The implicit save to the original project is a bit unexpected, but I guess that if that's being done in most of the cases, let's do it.

[ashdnazg]

Good point, I wasn't aware of the argument to save.
F&Sed

[barakwei]

GG!