templates/vhost/_proxy.erb misconfigures ProxyPassReverse

See here:
http://httpd.apache.org/docs/2.2/mod/mod_proxy.html#proxypassreverse

When enclosing ProxyPassReverse in a <Location> directive, you drop the
*first* argument, as it will be taken from the enclosing Location. The
second argument is the URL to which we are attempting to proxy.

Very simple change. Tested in my environment, works.
Merge branch 'master' of https://github.com/jrwilk01/puppetlabs-apache into proxy-pass-reverse
Update rspec definitions for the ProxyPassReverse location fix.
Document apache::apache_version
Merge pull request #641 from hunner/doc_apache_version

Document apache::apache_version
Merge pull request #613 from orionhealth/proxy-pass-reverse-fix

Proxy pass reverse fix