`ensure_arduino_installation.rb` doesn't create `arduino_library_location.rb`

[jgfoster]

Most of the libraries are working well with 1.0.0 but I've run into a snag on MAX431865. The problem is I can't install a customer prerequisite library:

bundle exec ensure_arduino_installation.rb
cd $(bundle exec arduino_library_location.rb)
ERROR: cd: /home/runner/Arduino/libraries: No such file or directory

[ianfixes]

Good catch, I will add the mkdir operation to ensure_arduino_installation.rb