pass engines.node to node-semver-service.heroku.com
use semver.io for great success
all tests passing; feature parity with diet, plus new server pro-tips
improve build output; all tests passing again
fix conflicts
Merge pull request #53 from heroku/use-semver-service

Use semver.io
use pipefail to force exit when `npm install` fails.
When restoring from cache, run `npm install` to ensure pre- and post-install scripts are run.
Merge pull request #56 from heroku/pipefail

use pipefail to force exit when `npm install` fails.
Merge pull request #57 from heroku/run-hooks

Ensure npm scripts are run after restoring cache
add npm-shrinkwrap.json cachebusting
redirect npm install's stderr to stdout
clear caches before slug compilation
Call nomnom in a subprocess so that it doesn't break the build
Merge pull request #58 from heroku/shrinkwrap

:shipit:
Merge pull request #59 from heroku/clear-node-gyp-cache

clear caches before slug compilation
Merge pull request #64 from playlist-media/diet

Call nomnom in a subprocess so that it doesn't break the build
> dev/null was superfluous
improve compile comments
use the new semver.io/node/resolve/{range} URL syntax