Energy consumption/ calculation

@zerone Thank you for sharing the interesting link.

However, this has been done for spiking-keras and I am using nengo_dl. Can we do something similar in nengo_dl? For instance, taking the example of the MNIST (Optimizing a spiking neural network — NengoDL 3.4.1.dev0 docs) tutorial with nengo_dl using LIF neurons. I would like to estimate the energy consumption for that model.