Fix typo in comment
Update README to state >= 2.6.5 is required

Earlier version of 2.6 won't work due to

http://bugs.python.org/issue2646
Merge branch 'readme-versions' into develop

* readme-versions:
  Update README to state >= 2.6.5 is required
Merge pull request #768 from cdodd/develop

Fix typo in comment