Train & Test Script Improvements

1. Cleanup

A large chunk of code in the train-and-test.py is not being referenced or used so I've removed it to pare down the script and make it easier to work with:

• Removed the StreamTee class which replicates the unix command tee
• Removed the train() function which has been replaced by the improved train_network()

2. Coming in other PRs to this branch.

I'll make smaller PRs to this train-test-improvements branch so the changes can be broken down easier.

Steps to Test:

Run the script using the train_config.ini configuration:

python train_and_test.py --train_gpu 0 --test_gpu 1 --run_inference True --config train_config.ini

Confirm that training proceeds as expected.