Add basic search bar with typeahead

The search bar gets a list of podcast titles that match the passes
string. It needs styling, and it should like to the podcast's page.

I'd like to add searching for episodes of podcasts too.
Add navbar with search form.
Javascript Runtime added to Gemfile.
Can now queue an episode from podcasts page.
Merge pull request #8 from epalace510/master

MInor changes and tweaks
Link search results to podcast's page
Merge branch 'search'