Fix readme example, documentation and error messages

README.rst

@@ -188,7 +188,7 @@ Toy environments which are text-based. There's no extra dependency to install, s
 .. code:: python
 
 	  import gym
-	  env = gym.make('FrozenLake')
+	  env = gym.make('FrozenLake-v0')
 	  env.reset()
 	  env.render()
 

gym/envs/atari/atari_env.py

@@ -7,7 +7,7 @@ from gym import utils
 try:
     import atari_py
 except ImportError:
-    raise error.DependencyNotInstalled("{}. (HINT: you can install Atari dependencies with 'pip install gym[atari].)'")
+    raise error.DependencyNotInstalled("{}. (HINT: you can install Atari dependencies with 'pip install gym[atari]'.)")
 
 import logging
 logger = logging.getLogger(__name__)

gym/envs/board_game/go.py

@@ -3,7 +3,7 @@ try:
     import pachi_py
 except ImportError as e:
     # The dependency group [pachi] should match the name is setup.py.
-    raise error.DependencyNotInstalled('{}. (HINT: you may need to install the Go dependencies via "pip install gym[pachi].)"'.format(e))
+    raise error.DependencyNotInstalled('{}. (HINT: you may need to install the Go dependencies via "pip install gym[pachi]".)'.format(e))
 
 import numpy as np
 import gym

gym/envs/mujoco/mujoco_env.py

@@ -7,7 +7,7 @@ from gym import error, spaces
 try:
     import mujoco_py
 except ImportError as e:
-    raise error.DependencyNotInstalled("{}. (HINT: you need to install mujoco_py, and also perform the setup instructions here: https://github.com/openai/mujoco-py/.)'".format(e))
+    raise error.DependencyNotInstalled("{}. (HINT: you need to install mujoco_py, and also perform the setup instructions here: https://github.com/openai/mujoco-py/.)".format(e))
 
 BIG=10000
 

gym/monitoring/monitor.py

@@ -71,7 +71,7 @@ class Monitor(object):
     to record every 100 episodes. ('count' is how many episodes have completed)
 
     Depending on the environment, video can slow down execution. You
-    can also use 'monitor.configure(video=lambda count: False)' to disable
+    can also use 'monitor.configure(video_callable=lambda count: False)' to disable
     video.
 
     Monitor supports multiple threads and multiple processes writing