Drop Python 2.6 #245

We have some specific code for python 2.6 but we don't have to support it because it is already EOL since 2013.

We don't have to drop it immediately, we can drop it:

• when a dev is frustrated with py 2.6
• when a dev needs a py 2.7 feature
• on April fool's

Reference: Stop Supporting Python 2.6 (For Free)