Use the global REGISTRY, in order : 
1) add exporter runtime metrics (fix  pryorda#9 )
2) add more metrics later (collection time for each object type)

This patch is intended to expose internal metrics on `/metrics` only for the default section (so people with multiple sections `?section=something` don't get duplicate metrics).

and declare metrics
vmware_exporter_build_info{version="..."}

use exporter_metrics in configuration file

E302 expected 2 blank lines