Remove hacks for no longer supported Py versiions

Signed-off-by: Lukas Puehringer <lukas.puehringer@nyu.edu>

Author: lukpueh

run_demo.py

@@ -6,11 +6,6 @@
 import time
 from shutil import copyfile, copytree, rmtree
 
-try:
-  input = raw_input
-except NameError:
-  pass
-
 NO_PROMPT = False
 
 def prompt_key(prompt):

run_demo_md.py

@@ -26,13 +26,8 @@
 import shutil
 import sys
 import tempfile
-import six
 import difflib
-
-if six.PY2:
-  import subprocess32 as subprocess
-else:
-  import subprocess
+import subprocess
 
 # The file pointed to by `INSTRUCTIONS_FN` contains `shell` code snippets that
 # may be extracted using the regex defined in `SNIPPET_PATTERN`, and executed
@@ -80,11 +75,6 @@
 1
 """
 
-# NOTE: Very ugly hack to make this work on Python 2
-if six.PY2:
-  EXPECTED_STDOUT = EXPECTED_STDOUT.replace("['", "[u'")
-
-
 # Setup a test directory with all necessary demo files and change into it. This
 # lets us easily clean up all the files created during the demo eventually.
 demo_dir = os.path.dirname(os.path.realpath(__file__))
@@ -113,15 +103,6 @@
       universal_newlines=True)
   stdout, _ = proc.communicate()
 
-  # NOTE: Ugly hack to filter deprecation warnings from output on EOLed versions
-  if sys.version_info < (3, 6):
-    stdout_filtered_list = []
-    for line in stdout.split("\n"):
-      if ("import cryptography.exceptions" not in line and
-          "CryptographyDeprecationWarning" not in line):
-        stdout_filtered_list.append(line)
-    stdout = "\n".join(stdout_filtered_list)
-
   # Fail if the output is not what we expected
   if stdout != EXPECTED_STDOUT:
     difflist = list(difflib.Differ().compare(