Kkumatani/dev dga

[kkumatani]

Highlight:

• Put back DGA functionality
• Added configuration files for DGA
• Clean up the default config file

Tested command:

python driver.py --server_config configs/server_config_wi_sm_dga.json
python driver.py --server_config configs/server_config_wi_rl_dga.json
python driver.py --server_config configs/server_config_wi_sm_rl_dga.json