Molecule 3.0 update script with all the little changes I had to make.

molecule-3-up.sh

#!/bin/bash
#
# Update things to be compatible with Molecule 3.0.
#
# This script is NOT idempotent, and should never be run again.
exit 1

export LINT_STRING="lint: |
  set -e
  yamllint .
  ansible-lint"

# Loop through all directories starting with "geerlingguy".
for dir in ./geerlingguy*/
do
  # cd into role directory.
  cd "$dir"

  # Change string `pip install molecule` to `pip install molecule yamllint ansible-lint` in .travis.yml
  sed -i '' 's/pip install molecule docker/pip install molecule yamllint ansible-lint docker/g' .travis.yml

  # Change and remove strings in molecule.yml
  sed -i '' '/[ ][ ]name: yamllint/d' molecule/default/molecule.yml
  sed -i '' '/[ ][ ]options:/d' molecule/default/molecule.yml
  sed -i '' '/[ ][ ][ ][ ]config-file:.*/d' molecule/default/molecule.yml
  sed -i '' 's/-playbook.yml/-converge.yml/g' molecule/default/molecule.yml
  sed -i '' '/[ ][ ]lint:/d' molecule/default/molecule.yml
  sed -i '' '/[ ][ ][ ][ ]name: ansible-lint/d' molecule/default/molecule.yml
  sed -i '' '/verifier:/d' molecule/default/molecule.yml
  sed -i '' '/[ ][ ]name: testinfra/d' molecule/default/molecule.yml
  sed -i '' '/[ ][ ][ ][ ]name: flake8/d' molecule/default/molecule.yml

  # Update lint block in molecule.yml file.
  perl -i -pe 's/lint:/$ENV{"LINT_STRING"}/g' molecule/default/molecule.yml

  # Move file `molecule/default/yaml-lint.yml` to `.yamllint` (if exists).
  if [ -f molecule/default/yaml-lint.yml ]; then
     mv molecule/default/yaml-lint.yml .yamllint
  fi

  # Move file `molecule/default/playbook.yml` to `molecule/default/converge.yml` (if exists).
  if [ -f molecule/default/playbook.yml ]; then
     mv molecule/default/playbook.yml molecule/default/converge.yml
  fi

  # cd back to parent directory.
  cd ..
done

Thanks for the script, it's useful to see how other are moving to 3.0. Please note that your lint configuration is slightly wrong.
For instance, if yamllint fails and ansible-lint succeeds, you won't get an error. I found that last Friday and used '&&' but current
documentation has been updated to use 'set -e', which is possibly better:

lint: |
  set -e
  yamllint .
  ansible-lint

@apatard - Thanks; and this is in reference to ansible/molecule#2575 — I'll update the gist.