Update application.html.erb

Removed CSS attributes which are not required in HTML 5.  Moved JS around.  This should prevent the JS from blocking the loading of the main content.  Could be further optimized by minification / concatenation of HTML / JS / CSS
It comes down I believe to how important metrics are.  If the person leaves the page before the tag is reached, the visit wouldn't be counted.  The tradeoff is having to parse JS earlier in the document, which is blocking.

Either location can be OK, depending on your specific needs.