Install sensu client on all nodes

Move sensu config into hiera and add the require for redis and rabbitmq
when installing the server.
Pull the community plugins down from github
Make ordering nicer
Move dashboard config into monitoring
Add user permissions and a vhost

These need to notify sensu as if they do not rabbitmq will not be
configured in time for sensu to work.
Merge branch 'master' of github.com:alphagov/pp-puppet into sensu-checks
Change password to one that RabbitMQ likes

RabbitMQ doesn't seem to like it when we use symbols in our passwords so
I am removing them all.
Merge pull request #47 from alphagov/sensu-checks

Sensu checks