Remove numGPUs/ithGPUs argument from CARLsim constructor

[hkashyap]

[benballintyn]

I am wondering about this. For CARLsim4 do we still need to specify which GPU want want to run on (e.g. 0, 1, 2, etc..) or is this being taken care of by CARLsim. In the printed output from sim.runNetwork() I no longer see anything specifying which GPU it was run on.

[hkashyap]

In CARLsim4, you do not need to specify the CPU/GPU ID at the CARLsim constructor. This is because you can use a separate CPU core or GPU card for each neuron group. Therefore, you specify the desired CPU/GPU at group level, through the createGroup() function. This section of the user guide discusses this:
http://uci-carl.github.io/CARLsim4/ch12_advanced_topics.html#ch12s3_multi_gpu