Search front-end beginnings

#### Auth service

- Cleaned auth service code a little bit
  - Moved current user check on "home" page from `marketplace.js` to `controllers/home.js`.

#### Search
Hopefully this helps write the CSS/design for the home page!

- Search bar in `templates/home.html.erb`
- Search route in `routes.rb`
  - Only searches openings for now (not users)
- Results render on home page when searching for matching terms
- Created seed data in `db/seeds/rb`. Check that file for valid search terms. (i.e. "Javascript")