build-essential:
python-dev:
libssl-dev:
libffi-dev:

build-essential:
python-dev:
python3-dev:
libssl-dev:
libffi-dev:

Add python3-dev to nodepool image
Add python3-dev to nodepool image

Zuul specifies that the pep8 tox venv uses python3, so we need
python3-dev to install the pep8 dependencies.

Signed-off-by: K Jonathan Harker <4a32a1ac4cf9729ec1fbb65946748ef0085119ad@ibm.com>
