More Rails 4.0 upgrade changes

1. Compared existing branch with empty Rails 4.0 project and
    made changes as needed.
 2. Fix find/first warning.
 3. Fix sqlite timeout issue.
    -- config/database.yml
    -- spec/vulnerabilities/insecure_dor_spec.rb

public/robots.txt

@@ -1,5 +1,5 @@
 # See http://www.robotstxt.org/wc/norobots.html for documentation on how to use the robots.txt file
 #
 # To ban all spiders from the entire site uncomment the next two lines:
-# User-Agent: *
+# User-agent: *
 # Disallow: /