bundle install or bundle update
bower install
bundle exec middleman serve
bundle exec middleman build

on Mac OSX The following is needed to properly execute the first line to get ffi t install (might need to repeat again without env variables after ffi installs if other packages fail.)

LDFLAGS="-L/usr/local/opt/libffi/lib" PKG_CONFIG_PATH="/usr/local/opt/libffi/lib/pkgconfig" bundle install --path vendor

Alternatively compile it using a docker container:

UID=${UID} GID=${GID} docker-compose up