title: Pint Python module in MetPy - pint.UnitRegistry TypeError - unexpected keyword argument
body: <p>I'm trying to use a newish Python package for meteorological purposes, MetPy. It relies on using Pint to support units. I'm struggling to import any of the basic modules of MetPy because of an error in the Pint/units part, which is part of the code for importing all sub-modules. (This isn't my code, this is from the package)</p>
  
  <pre><code>from __future__ import division
  import pint
  import numpy as np
  units = pint.UnitRegistry(autoconvert_offset_to_baseunit=True)
  
  TypeError: __init__() got an unexpected keyword argument 'autoconvert_offset_to_baseunit' 
  </code></pre>
  
  <p>In the basic Pint documentation here (<a href="http://pint.readthedocs.org/en/latest/nonmult.html" rel="nofollow">http://pint.readthedocs.org/en/latest/nonmult.html</a>) this is a common command as an 'alternative to raising an error', so I can't work out why it isn't working here.</p>
  
  <p>Does anyone have any experience of Pint and know what might be the problem? I'm new to Python and haven't used Pint before today.</p>