[WIP] Add Rackspace Auto Scale support

[bison]

Adds support for Rackspace Auto Scale.

Docs: https://developer.rackspace.com/docs/autoscale/v1/developer-guide/

Fixes #418

[bison]

This is optional, and may not be in the response when requesting a launch configuration -- zero is actually not a valid value. Should I ditch the Args type and have that just be a map[string]interface{}?

[jrperritt]

I think you've got the right idea here. We want the fields to be as specific as possible, so for some things we have no choice but map[string]interface{} but we want that to be a last resort. If you don't want the DrainingTimeout field to show up if it's empty, you can use the encoding/json package (instead of the mapstructure package) to unmarshal the JSON into the Configuration and use json:"draining_timeout,omitempty" for the field's struct tag.

[coveralls]

Coverage decreased (-0.01%) to 79.959% when pulling 66ce2e7 on bison:rax-auto-scale into 3dc5217 on rackspace:master.

[coveralls]

Coverage increased (+0.01%) to 79.984% when pulling cce6f7f on bison:rax-auto-scale into 3dc5217 on rackspace:master.

[coveralls]

Coverage increased (+0.04%) to 80.008% when pulling 9d758a8 on bison:rax-auto-scale into 3dc5217 on rackspace:master.

[coveralls]

Coverage increased (+0.05%) to 80.017% when pulling ff2278f on bison:rax-auto-scale into 3dc5217 on rackspace:master.

[coveralls]

Coverage increased (+0.08%) to 80.047% when pulling 53a18f1 on bison:rax-auto-scale into 3dc5217 on rackspace:master.

[coveralls]

Coverage increased (+0.1%) to 80.071% when pulling 3a0d82b on bison:rax-auto-scale into 3dc5217 on rackspace:master.

[coveralls]

Coverage increased (+0.1%) to 80.1% when pulling c6394f5 on bison:rax-auto-scale into 3dc5217 on rackspace:master.

[bison]

So, all the bits for webhooks are done, and the diff is already pretty big. Would it be easier if I close this and open a separate PR for each package (webhooks, policies, launch, and groups) as I get to those, or do you prefer one giant PR?

[jrperritt]

Smaller PRs would be appreciated.

[bison]

Cool. Closing this.