initial working version

@feanil @jarv  Inventory script targeting the ASG.  Could be rolled into ec2.py, but I'd rather get our version to the latest and fix it to use profiles before integrating.

Output looks like so:
```
{
  "InService": [
    "10.0.47.127", 
    "10.0.30.137"
  ], 
  "Terminating:Wait": [
    "10.0.11.83"
  ], 
  "e-d-CommonClusterServerAsGroup": [
    "10.0.47.127", 
    "10.0.46.174", 
    "10.0.48.104"
  ], 
  "e-d-CommonClusterServerAsGroup_InService": [
    "10.0.47.127", 
    "10.0.46.174", 
    "10.0.48.104"
  ]
}
```
Seems weird to parse args inside the class, I think it makes more sense to do the arg parsing before the class instantiation and pass in a set of configurations to the class. Which in this case is just the profile name.