SEO to public side of site

Update bundler to match what Heroku is using.
Add meta-tags gem to help with SEO.
Added robots, content type, description, title, canonical and keyword
tags to public pages.
Remove SEO keywords tag

Remove keywords meta tag as search engines no longer use it,
http://searchenginewatch.com/article/2067564/How-To-Use-HTML-Meta-Tags.
Only allow indexing of pages within Honolulu Answers.
Update description tag to reference article preview field