issue-221: Adds a frontend:setup task and also passthru for target-hooks

[sarahjean]

Relates to #221

[grasmash]

Need to update description.

[sarahjean]

@grasmash It is different, is "Uses project.yml hooks to run custom defined commands to setup front end dependencies for frontend:build." confusing?

[grasmash]

oh, I guess I see what you did there. The frontend:build reference confused me initially.

[grasmash]

Nothing appears to actually trigger frontend:setup. Should it be a dependency of frontend:build?

[sarahjean]

@grasmash The idea is that frontend:build can be run without triggering frontend:setup and would therefore run faster since it doesn't have to do npm install or whatever. It would make more sense to trigger it for local:setup and/or for a Travis build but not have it run every time you do a frontend:build.

[grasmash]

In that case, I'd introduce a frontend target that depends on frontend:install and frontend:build. setup can then depend on frontend.

[grasmash]

Closing in favor of #291