Why is python setup.py saying invalid command “bdist_wheel” on Travis CI?

My Python package has a setup.py which builds fine locally on Ubuntu Trusty and on a fresh Vagrant Ubuntu Trusty VM when I provision it like this:

sudo apt-get install python python-dev --force-yes --assume-yes --fix-broken
curl --silent --show-error --retry 5 https://bootstrap.pypa.io/get-pip.py | sudo python2.7
sudo -H pip install setuptools wheel virtualenv --upgrade

But when I do the same on a Travis CI Trusty Beta VM:

- sudo apt-get install python python-dev --force-yes --assume-yes --fix-broken
- curl --silent --show-error --retry 5 https://bootstrap.pypa.io/get-pip.py | sudo python2.7
- sudo -H pip install setuptools wheel virtualenv --upgrade

I get:

python2.7 setup.py bdist_wheel
usage: setup.py [global_opts] cmd1 [cmd1_opts] [cmd2 [cmd2_opts] ...]
   or: setup.py --help [cmd1 cmd2 ...]
   or: setup.py --help-commands
   or: setup.py cmd --help
error: invalid command "bdist_wheel"

This Why can I not create a wheel in python? is related but note I am installing wheel and upgrading setuptools.