title: No module named 'core' when using pyping for Python 3
body: <p>I am trying to import <code>pyping</code> for Python 3 but I am getting below error:</p>
  
  <pre><code>virt01@virt01:~/Python_Admin$ python3
  Python 3.4.3 (default, Oct 14 2015, 20:28:29)
  [GCC 4.8.4] on linux
  Type "help", "copyright", "credits" or "license" for more information.
  &gt;&gt;&gt; import pyping
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
    File "/usr/local/lib/python3.4/dist-packages/pyping/__init__.py", line 3, in &lt;module&gt;
      from core import *
  ImportError: No module named 'core'
  &gt;&gt;&gt;
  </code></pre>
  
  <p><em>Update 1</em></p>
  
  <pre><code>virt01@virt01:~/Python_Admin$ ls /usr/local/lib/python3.4/dist-packages/pyping/
  core.py  __init__.py  __pycache__
  </code></pre>