language: python
python:
  - "2.7"
  - "3.3"
  - "3.4"
  - "3.5"
  - "3.5-dev" # 3.5 development branch
  - "nightly" # currently points to 3.6-dev
install: "pip install ."
script: "py.test -c pytest-travis.ini"

language: python
python:
  - "2.7"
  - "3.5"
  - "3.5-dev" # 3.5 development branch
  - "nightly" # currently points to 3.6-dev
install: "pip install ."
script: "py.test -c pytest-travis.ini"

Drop tests for Python 3.3 & 3.4
Drop tests for Python 3.3 & 3.4

We can fairly safely assume that those are no longer in use.
