add scikeras package to install instructions

[erinmgraham]

ep 05 has gridsearch that uses scikeras package and needs to be installed with rest of the environment setup

[erinmgraham]

Added to setup.md and setup-gpu.md

[erinmgraham]

Tried adding scikeras to conda create call but it is "not available from current channels. Need to use pip instead pip install scikeras

[erinmgraham]

Modified CPU and GPU setup files with more detail about creating environments and added scikeras to pip install