Not compatible with most recent version of DeepXDE

[qjiao1]

Thanks for sharing the code with community.

It seems there were major updates on DeepXDE package since this code was published, so would you please update this code
for indentation problem accordingly?

If install the newest DDE, I got the error "module 'deepxde' as no attribute 'apply'", but if I return to v0.8.0, the problem will be gone.

Many thanks.

[lululxvi]

Use dde.utils.apply