Ensure config files are in place so environment can be loaded for asset precompilation.
Missing change from 0e04023eb98fb4bdd922e511ec304600648b760c.
Ignore precompiled assets.
Precompile all JS and CSS files, not just application.js and application.css.

(cherry picked from commit cf8ebef21e540887b4f05c84368ffa4aedea8b33)