Hammer CLI

Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1253820

Description of problem:
Hammer returns inconsistent capitalization in its json output. For example, a user trying to parse the id's in an output may have to handle 'ID', 'Id', and 'id'.

Version-Release number of selected component (if applicable):
Satellite 6.1 GA

How reproducible:
Always

Steps to Reproduce:
1. run one of the two commands detailed in Additional Info, or your own choice.
2. run at least one more command
3. Check consistency for returned keys

Actual results:
keys are inconsistently capitalized

Expected results:
keys are inconsistently capitalized. I prefer lowercase for ease

Additional info:

hammer --output=json organization info --id="31" 
{
  "Id": 31,
  "Name": "KVybjk",
  "Users": [

  ],
  "Smart proxies": [
    {
      "name": "rhsm-qe-1.rhq.lab.eng.bos.redhat.com",
      "id": 1,
      "url": "https://rhsm-qe-1.rhq.lab.eng.bos.redhat.com:9090" 
    }
...
  "Templates": [
    {
      "id": 44,
      "name": "Boot disk iPXE - generic host",
      "template_kind_id": 1,
      "template_kind_name": "Bootdisk" 
    },

hammer -v -u --output=json activation-key info --id="57" 
{
  "Name": "rI6jNBJVaR",
  "ID": 57,
  "Description": null,
  "Content Host Limit": "Unlimited",
  "Auto Attach": true,
  "Lifecycle Environment": null,
  "Content View": null,
  "Host Collections": {
  }
}