Add check to see which member the active application default credentials are for

[jessesomerville]

No description provided.

[jessesomerville]

Partial fix in PR #35

The following error may also be caused by issues with the active ADC on the users local machine:

ERROR   eiam crashed due to an unhandled error        error=an error occurred while fetching service accounts: Get "https://iam.googleapis.com/v1/projects/example/serviceAccounts?alt=json&prettyPrint=false": oauth2: cannot fetch token: 400 Bad Request
Response: {
  "error": "invalid_grant",
  "error_description": "Bad Request"
}