Log to haproxy.log via syslog

- Update Gemfile to use latest berkshelf gem fixing bug to allow use of HTTPS enabled community site.
- Fixed bug in recipes/default where setting httpchk option overwrote the options array with a string.
- Creates a config file in rsyslog.d processing logs from haproxy.

We don't seem to have an explicit dependency on either the `rs-base` or `rsyslog` cookbooks which make sure that rsyslog is configured and the service exists; since this recipe is assuming it exists we need to have that dependency and probably should use an `include_recipe` rather than just defining this service resource here.