Trainin docs and buildout "Installing Plone for the Training"

here: https://training.plone.org/5/plone_training_config/instructions.html

I had to do

./bin/pip install wheel

before

./bin/pip install -r requirements.txt

otherwise you get

error: invalid command 'bdist_wheel'

To use C implementation of PyYaml you've to:

apt-get install libyaml-dev

for buildout to find yaml.h when compiling