2.6 has no OrderedDict in collections

[AvdN]

Should take out support for 2.6 from the setup.py file

Python 2.6.8 (unknown, Jul 27 2013, 05:35:35) 
[GCC 4.7.2] on linux3
Type "help", "copyright", "credits" or "license" for more information.
>>> import yaml
>>> import yamlordereddictloader
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/data1/envs/test_yamlordereddictloader/lib/python2.6/site-packages /yamlordereddictloader.py", line 7, in <module>
    from collections import OrderedDict
ImportError: cannot import name OrderedDict

[fmenabe]

This is because in python2.6, OrderedDict is not in collections module (which is standard) but in the ordereddict module. I update the code and the setup file for automatically install and use ordereddict with python2.6.