Grow bastion root volume

The default root volume for instances is 8GB. This change ensures that
the root volume for the bastion instance (plays a dual role as a
monitoring server) is 128GB.
Remove use of collectd_hostname

`collectd_hostname` was being used to populate the Collectd
configuration file's `Hostname` setting. If omitted, Collectd uses the
`gethostname(2)` system call to automatically set `Hostname`. This
behavior is much more desirable for EC2.

See also: https://github.com/azavea/ansible-collectd/pull/1
Merge branch 'feature/remove-collectd-hostname' into develop
Fix Apache and Nginx race condition with /var/www/html

Kibana uses `/var/www/html` as its web root and Nginx attempts to serve
its static assets from there. Later, Apache is installed for the
Graphite Web interface, and the Apache package dumps a test site into
`/var/www/html`. Unfortunately, this overwrites the static assets that
Kibana and Apache's test site have in common (`index.html`).

This changeset makes the Graphite installation go first, followed by
Kibana. In addition, the Apache installation also removes the test site
*if* `apache_delete_default_site` is `True`.

See also: https://github.com/azavea/ansible-apache2/pull/2
Merge branch 'feature/fix-apache-nginx-race' into develop
Make 8081 the Kibana port globally
Template and parameter file references were broken
Add RELP to nyc-trees.logstash
Ensure that Apache collectd plugin uses apache_port
Add variable grouping for monitoring servers
Create staging variable grouping; add Amazon NTP servers
Create VPC stack outputs for VPC ID and bastion subnet and IP
Create Packer template for cutting the monitoring AMI
Create deployment helper script to aid in creating AMIs
Add support for creating VPC stack to deployment helper
Move VPC stack creation into deployment-helper
Move data store stack creation into deployment helper
Move monitoring AMI and VPC stack update into deployment helper
Update README sections for deploying VPC and data store stacks
Add elbAppServer and elbTileServer as defaults