Fix heroku build

[dpikt]

Node-sass was giving us trouble - we have to force a rebuild using yarn remove.
yarnpkg/yarn#1832

Also:

• Made yarn run storybook:build a heroku-specific script
• Made sass a dev dependency
• Removed prepublish linting

[davemcorwin]

weird. So looking at the package.json

1. shouldn't documentation and jest be devDependencies?
2. what is the sass module?
3. have you seen this issue consistently even after clearing the npm cache?

[dpikt]

1. Yes
2. I don't know, let me see if it compiles without it
3. Yes. I don't think Heroku is using the yarn cache anyway.

[dpikt]

@davemcorwin switched up the dependencies. I removed sass since it wasn't doing anything- I probably mistakenly thought it was a peer dependency of node-sass.

[davemcorwin]

word