datadog agent run should fail if api key is an application key

[antoniobeyah]

**Output of the info page **

-> kubectl exec datadog-datadog-6cfzc -it /etc/init.d/datadog-agent status
Warning: Known bug in Linux Kernel 3.18+ causes 'status' to fail.
Calling 'info', instead...
2017-10-10 16:12:03,418 | WARNING | dd.collector | utils.service_discovery.config(config.py:31) | No configuration backend provided for service discovery. Only auto config templates will be used.
====================
Collector (v 5.17.2)
====================

  Status date: 2017-10-10 16:11:57 (6s ago)
  Pid: 18
  Platform: Linux-4.12.14-coreos-x86_64-with-debian-8.9
  Python Version: 2.7.13, 64bit
  Logs: <stderr>, /var/log/datadog/collector.log

  Clocks
  ======

    NTP offset: -0.0221 s
    System UTC time: 2017-10-10 16:12:03.522747

  Paths
  =====

    conf.d: /etc/dd-agent/conf.d
    checks.d: /opt/datadog-agent/agent/checks.d

  Hostnames
  =========

    ec2-hostname: <snip>
    local-ipv4: <snip>
    socket-hostname: datadog-datadog-6cfzc
    hostname: <snip>
    local-hostname: <snip>
    instance-id: <snip>
    socket-fqdn: datadog-datadog-6cfzc

  Checks
  ======

    kubernetes_state (5.17.2)
    -------------------------
      - instance #0 [OK]
      - Collected 0 metrics, 0 events & 0 service checks

    kubernetes (5.17.2)
    -------------------
      - instance #0 [OK]
      - Collected 672 metrics, 0 events & 3 service checks

    ntp (5.17.2)
    ------------
      - Collected 0 metrics, 0 events & 0 service checks

    disk (5.17.2)
    -------------
      - instance #0 [OK]
      - Collected 32 metrics, 0 events & 0 service checks

    docker_daemon (5.17.2)
    ----------------------
      - instance #0 [OK]
      - Collected 262 metrics, 1 event & 1 service check


  Emitters
  ========

    - http_emitter [OK]

2017-10-10 16:12:03,901 | WARNING | dd.dogstatsd | utils.service_discovery.config(config.py:31) | No configuration backend provided for service discovery. Only auto config templates will be used.
====================
Dogstatsd (v 5.17.2)
====================

  Status date: 2017-10-10 16:11:56 (7s ago)
  Pid: 15
  Platform: Linux-4.12.14-coreos-x86_64-with-debian-8.9
  Python Version: 2.7.13, 64bit
  Logs: <stderr>, /var/log/datadog/dogstatsd.log

  Flush count: 330
  Packet Count: 0
  Packets per second: 0.0
  Metric count: 1
  Event count: 0
  Service check count: 0

====================
Forwarder (v 5.17.2)
====================

  Status date: 2017-10-10 16:11:59 (4s ago)
  Pid: 14
  Platform: Linux-4.12.14-coreos-x86_64-with-debian-8.9
  Python Version: 2.7.13, 64bit
  Logs: <stderr>, /var/log/datadog/forwarder.log

  Queue Size: 4844275 bytes
  Queue Length: 839
  Flush Count: 800
  Transactions received: 839
  Transactions flushed: 0
  Transactions rejected: 0
  API Key Status: API Key is invalid


======================
Trace Agent (v 5.17.2)
======================

  Pid: 13
  Uptime: 3312 seconds
  Mem alloc: 877208 bytes

  Hostname: datadog-datadog-6cfzc
  Receiver: localhost:8126
  API Endpoint: https://trace.agent.datadoghq.com

  Bytes sent (1 min): 0
  Traces sent (1 min): 0
  Stats sent (1 min): 0

-> kubectl exec datadog-datadog-6cfzc -it /etc/init.d/datadog-agent flare
2017-10-10 15:49:32,713 | WARNING | dd.collector | utils.service_discovery.config(config.py:31) | No configuration backend provided for service discovery. Only auto config templates will be used.
2017-10-10 15:49:32,761 | WARNING | dd.collector | utils.service_discovery.config(config.py:31) | No configuration backend provided for service discovery. Only auto config templates will be used.
2017-10-10 15:49:36,145 | INFO | dd.collector | utils.flare(flare.py:176) |   * log permissions on collected files
2017-10-10 15:49:36,145 | INFO | dd.collector | utils.flare(flare.py:155) | Saving all files to /tmp/datadog-agent-2017-10-10-15-49-32.tar.bz2
/tmp/datadog-agent-2017-10-10-15-49-32.tar.bz2 is going to be uploaded to Datadog.
Do you want to continue [Y/n]? Y
Please enter your email: <snip>
2017-10-10 15:50:08,831 | INFO | dd.collector | utils.flare(flare.py:215) | Uploading /tmp/datadog-agent-2017-10-10-15-49-32.tar.bz2 to Datadog Support
The upload failed:
Your request is incorrect: Invalid inputs: 'API key unknown'

Additional environment details (Operating System, Cloud provider, etc):
kubernetes running on coreos. datadog agent is running as a daemonset

Steps to reproduce the issue:

1. Create a docker image using the docker-dd-agent with an 'application key' instead of an 'api key'

Describe the results you received:
docker container continued to run with without reporting any failures and it failed to report any data.

Describe the results you expected:
docker container should have failed or metrics should have been reported.