Integrate coach.py params with distributed Coach. (#42)

* Integrate coach.py params with distributed Coach.
* Minor improvements
- Use enums instead of constants.
- Reduce code duplication.
- Ask experiment name with timeout.

rl_coach/utils.py

@@ -23,6 +23,7 @@ import signal
 import sys
 import threading
 import time
+import traceback
 from multiprocessing import Manager
 from subprocess import Popen
 from typing import List, Tuple
@@ -30,6 +31,8 @@ from typing import List, Tuple
 import atexit
 import numpy as np
 
+from rl_coach.logger import screen
+
 killed_processes = []
 
 eps = np.finfo(np.float32).eps