add Speed model

Speed model captures delay rate, animal, and text blurb
added seed file to populate database
refactor js to use data from rails for speed settings

add data attributes for animal (not used yet) and blurb (used)
to html buttons for animals
pick up these attributes to update blurb using setBlurb() in js
experimented with -- then abandoned -- getting speed settings as JSON
object from Rails -- issues with synchronization made it needlessly complicated