title: pwntools python not importing
body: <pre><code>$ apt-get update
  $ apt-get install python2.7 python-pip python-dev git libssl-dev libffi-dev build-essential
  $ pip install --upgrade pip
  $ pip install --upgrade pwntools
  </code></pre>
  
  <p>After I ran the above command to install pwntools when I go to python and import pwntools it shows the following error.</p>
  
  <pre><code>&gt; christos@ubuntu:~$ python Python 2.7.12 (default, Dec  4 2017,
  &gt; 14:50:18) [GCC 5.4.0 20160609] on linux2 Type "help", "copyright",
  &gt; "credits" or "license" for more information.
  &gt; &gt;&gt;&gt; import pwn Traceback (most recent call last):   File "&lt;stdin&gt;", line 1, in &lt;module&gt;   File
  &gt; "/home/christos/.local/lib/python2.7/site-packages/pwn/__init__.py",
  &gt; line 4, in &lt;module&gt;
  &gt;     from pwn.toplevel import *   File "/home/christos/.local/lib/python2.7/site-packages/pwn/toplevel.py",
  &gt; line 20, in &lt;module&gt;
  &gt;     import pwnlib   File "/home/christos/.local/lib/python2.7/site-packages/pwnlib/__init__.py",
  &gt; line 43, in &lt;module&gt;
  &gt;     importlib.import_module('.%s' % module, 'pwnlib')   File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module
  &gt;     __import__(name)   File "/home/christos/.local/lib/python2.7/site-packages/pwnlib/dynelf.py",
  &gt; line 57, in &lt;module&gt;
  &gt;     from pwnlib import elf   File "/home/christos/.local/lib/python2.7/site-packages/pwnlib/elf/__init__.py",
  &gt; line 9, in &lt;module&gt;
  &gt;     from pwnlib.elf.corefile import Core   File "/home/christos/.local/lib/python2.7/site-packages/pwnlib/elf/corefile.py",
  &gt; line 85, in &lt;module&gt;
  &gt;     from pwnlib.elf.elf import ELF   File "/home/christos/.local/lib/python2.7/site-packages/pwnlib/elf/elf.py",
  &gt; line 55, in &lt;module&gt;
  &gt;     from elftools.elf.enums import ENUM_P_TYPE ImportError: cannot import name ENUM_P_TYPE
  </code></pre>