(RE-7014) Add support for statsd

They way we were using graphite was incorrect for the type of data we were sending it.  statsd is the appropriate mechanism for our needs.
statsd and graphite are mutually exclusive and configuring statsd will take precendence over Graphite.  Example of configuration in vmpooler.yaml.example

Gemfile

@@ -1,15 +1,18 @@
 source ENV['GEM_SOURCE'] || 'https://rubygems.org'
 
 gem 'json', '>= 1.8'
+gem 'net-ldap', '<= 0.11'
 gem 'rack', '>= 1.6'
 gem 'rake', '>= 10.4'
 gem 'rbvmomi', '>= 1.8'
 gem 'redis', '>= 3.2'
 gem 'sinatra', '>= 1.4'
+gem 'statsd-ruby', '>= 1.3.0'
 
 # Test deps
 group :test do
   gem 'rack-test', '>= 0.6'
   gem 'rspec', '>= 3.2'
+  gem 'simplecov', '>= 0.11.2'
   gem 'yarjuf', '>= 2.0'
 end