Baseline experiments for the BabyAI environment

We perform a collection of baseline experiments within the BabyAI environment on the GoToLocal task, see the projects/babyai_baselines/experiments/go_to_local directory. For instance, to train a model using PPO, run

python main.py go_to_local.ppo --experiment_base projects/babyai_baselines/experiments

Note that these experiments will be quite slow when not using a GPU as the BabyAI model architecture is surprisingly large. Specifying a GPU (if available) can be done from the command line using hooks we created using gin-config. E.g. to train using the 0th GPU device, add

--gp "machine_params.gpu_id = 0"

to the above command.