Simplify examples to no longer use logging or Client.is_logged_in

The logging module is no longer required to get diagnostic output
since we use `stderr` by default regardless of the logging module.
Which means that the logging module will only give a more verbose
output than is necessary.

Client.is_logged_in checking is no longer necessary since all HTTP
request handling now raise an exception if they fail so those chunks
are also gone.

examples/deleted.py

@@ -1,16 +1,8 @@
 import discord
-import logging
-
-# Set up the logging module to output diagnostic to the console.
-logging.basicConfig()
 
 client = discord.Client()
 client.login('email', 'password')
 
-if not client.is_logged_in:
-    print('Logging in to Discord failed')
-    exit(1)
-
 @client.event
 def on_ready():
     print('Connected!')

examples/echo.py

@@ -1,16 +1,8 @@
 import discord
-import logging
-
-# Set up the logging module to output diagnostic to the console.
-logging.basicConfig()
 
 client = discord.Client()
 client.login('email', 'password')
 
-if not client.is_logged_in:
-    print('Logging in to Discord failed')
-    exit(1)
-
 @client.event
 def on_ready():
     print('Connected!')

examples/edits.py

@@ -1,17 +1,9 @@
 import discord
 import time
-import logging
-
-# Set up the logging module to output diagnostic to the console.
-logging.basicConfig()
 
 client = discord.Client()
 client.login('email', 'password')
 
-if not client.is_logged_in:
-    print('Logging in to Discord failed')
-    exit(1)
-
 @client.event
 def on_ready():
     print('Connected!')

examples/reply.py

@@ -1,16 +1,8 @@
 import discord
-import logging
-
-# Set up the logging module to output diagnostic to the console.
-logging.basicConfig()
 
 client = discord.Client()
 client.login('email', 'password')
 
-if not client.is_logged_in:
-    print('Logging in to Discord failed')
-    exit(1)
-
 @client.event
 def on_message(message):
     if message.content.startswith('!hello'):