message: [docs] more specific about python versions
diff: @@ -4,8 +4,9 @@ Installation & Configuration
  Getting Started
  ---------------
  -Superset is tested using Python 2.7 and Python 3.4+. Python 3 is the recommended version,
  -Python 2.6 won't be supported.
  +Superset is tested against Python ``2.7`` and Python ``3.4``.
  +Airbnb currently uses 2.7.* in production. We do not plan on supporting
  +Python ``2.6``.
  OS dependencies
  