added smoke tests of ddpg (#734)

baselines/ddpg/test_smoke.py

@@ -0,0 +1,17 @@
+from baselines.run import main as M
+
+def _run(argstr):
+    M(('--alg=ddpg --env=Pendulum-v0 --num_timesteps=0 ' + argstr).split(' '))
+
+def test_popart():
+    _run('--normalize_returns=True --popart=True')
+
+def test_noise_normal():
+    _run('--noise_type=normal_0.1')
+
+def test_noise_ou():
+    _run('--noise_type=ou_0.1')
+
+def test_noise_adaptive():
+    _run('--noise_type=adaptive-param_0.2,normal_0.1')
+