You can wrap these three lines in `if [ "$TOXENV" = "py34" ]` like this

```yaml
  - if [ "$TOXENV" = "py34" ]; then
        sudo apt-add-repository -y ppa:fkrull/deadsnakes;
        sudo apt-get update;
        sudo apt-get install python3.4;
    fi
```

...to speed up tests with other versions and save the world by saving CPU time :)