Python 3 port: use input() instead of raw_input()

On Python 2, input() has a different behavior, including an evaluation
of the obtained string.  On Python 3, it just returns the stripped
string.

Let's hand off the difference handling to six.

PS: we won't use use six.moves.input() on the failtest_ugly.py file,
given that it's intended to be a bad example.
Signed-off-by: NCleber Rosa <crosa@redhat.com>

avocado/utils/genio.py

@@ -20,6 +20,8 @@ import logging
 import os
 import time
 
+from six.moves import input
+
 from . import path as utils_path
 
 log = logging.getLogger('avocado.test')
@@ -99,7 +101,7 @@ def ask(question, auto=False):
     if auto:
         log.info("%s (y/n) y" % question)
         return "y"
-    return raw_input("%s (y/n) " % question)
+    return input("%s (y/n) " % question)
 
 
 def read_file(filename):

examples/tests/failtest_ugly.py

@@ -6,7 +6,7 @@ import sys
 
 sys.stdout.write("Direct output to stdout\n")
 sys.stderr.write("Direct output to stderr\n")
-raw_input("I really want some input on each import")
+input("I really want some input on each import")
 sys.stdin = 'This is my __COOL__ stdin'
 sys.stdout = 'my stdout'
 sys.stderr = 'my stderr'

scripts/avocado-run-testplan

@@ -23,6 +23,8 @@ import sys
 
 import argparse
 
+from six.moves import input
+
 
 class Parser(argparse.ArgumentParser):
 
@@ -89,9 +91,9 @@ class App(object):
 
             result = None
             while True:
-                result = raw_input("Result ([P]ass, [F]ail, [S]kip): ")
+                result = input("Result ([P]ass, [F]ail, [S]kip): ")
                 if result in RESULT_MAP.keys():
-                    notes = raw_input("Additional Notes: ")
+                    notes = input("Additional Notes: ")
                     break
             print("")
 
@@ -99,7 +101,7 @@ class App(object):
                                  "result": RESULT_MAP.get(result),
                                  "notes": notes.strip()})
 
-        user = raw_input("Your identification [%s]: " % getpass.getuser())
+        user = input("Your identification [%s]: " % getpass.getuser())
         if not user:
             user = getpass.getuser()
         self.user_identification = user