fix for installing pymix on ubuntu using python 2.6 or 2.7

pymix_fix.py

# 3 steps
# 1) in setup.py
# change
from distutils.core import setup, Extension,DistutilsExecError

#to:

from distutils.core import setup, Extension
from distutils.errors import DistutilsExecError

# 2) in setup.py
# change 
numpypath = prefix + '/lib/python' +pyvs + '/site-packages/numpy/core/include/numpy' # path to arrayobject.h

# to
# (locate arrayobject.h) - for me this path was
numpypath = '/usr/share/pyshared/numpy/core/include/numpy'


# Finally
# 3) in /usr/local/lib/python2.7/dist-packages/AminoAcidPropertyPrior.py
# change
as =  alpha.pop(0)   # (line 170)

# to
dummy = alpha.pop(0) # 'as' is a reserved keyword