Secret payload retrieval fails with 406

[Melissa Kam]

Attempting to get a secret's payload with any mime-type is failing with a 406.

Steps to Recreate:
POST http://.../v1/test_tenant/secrets
{
  "name": "AES key",
  "expiration": "2014-02-28T19:14:44.180394",
  "algorithm": "aes",
  "bit_length": 256,
  "cypher_type": "CBC",
  "payload": "gF6+lLoF3ohA9aPRpt+6bQ==",
  "payload_content_type": "application/octet-stream",
  "payload_content_encoding": "base64"
}

GET http://.../v1/test_tenant/secrets/{secret_ref}
Headers:
Accept: application/octet-stream

Response:
406 Not Acceptable
Accept of '[]' is not supported.

[John Vrbanac (john.vrbanac)]

Verified as of Git: 44fcce118d1d7115c8dfbdc1629b29cfb63c4027