Potential bug in Mixture of Experts Model

**Describe the bug**
Given issue #129 , we suspect there may be an issue with copying MoE models

**To Reproduce**
To explore this, create an MoE model and try to deep copy it. See if error results.

**Expected behavior**
We should be able to create a copy of an MoE model.

Also need to add new tests to test_moe.py to confirm copying of model is working correctly (previously issue #134 )