HTTP Code 500 Returned on bad CA resource in URL

Recreate Steps
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$curl -H 'content-type:application/json' -H "X-Auth-Token:$TOKEN" http://localhost:9311/v1/cas ; echo

{"cas": ["http://localhost:9311/v1/cas/23f269d1-2def-4ec7-8036-3b29c138ef45", "http://localhost:9311/v1/cas/2d7041bc-bbd1-468e-9bc5-666d57347cb3"], "total": 2}

$ curl -H 'content-type:application/json' -H "X-Auth-Token:$TOKEN" http://localhost:9311/v1/cas/23f269d1-2def-4ec7-8036-3b29c138ef45 ; echo

{"status": "ACTIVE", "updated": "2015-09-17T02:11:52.054309", "created": "2015-09-17T02:11:52.054309", "plugin_name": "barbican.plugin.simple_certificate_manager.SimpleCertificatePlugin", "meta": [{"ca_signing_certificate": "XXXXXXXXXXXXXXXXX"}, {"intermediates": "YYYYYYYYYYYYYYYY"}, {"description": "Certificate Authority - Simple CA"}, {"name": "Simple CA"}], "ca_id": "23f269d1-2def-4ec7-8036-3b29c138ef45", "plugin_ca_id": "Simple CA", "expiration": "2015-09-18T02:11:52.047218"}

$barbican dmccowan$ curl -H 'content-type:applicatison' -H "X-Auth-Token:$TOKEN" http://localhost:9311/v1/cas/23f269d1-2def-4ec7-8036-3b29c138ef45/foo ; echo
{"code": 500, "description": "Certificate Authority retrieval failure seen - please contact site administrator.", "title": "Internal Server Error"}

Traceback:
----------------
2015-09-17 08:03:01.771 69275 ERROR barbican.api.controllers [req-d4aed034-c754-4213-95eb-34690c2844cf aef5916109094125b7e52fdd7c43ecc2 0b0ea955139a4a0690a86f2d95310042 - default default] Certificate Authority retrieval failure seen - please contact site administrator.
2015-09-17 08:03:01.771 69275 ERROR barbican.api.controllers Traceback (most recent call last):
2015-09-17 08:03:01.771 69275 ERROR barbican.api.controllers File "/Users/dmccowan/barbican/barbican/api/controllers/__init__.py", line 104, in handler
2015-09-17 08:03:01.771 69275 ERROR barbican.api.controllers return fn(inst, *args, **kwargs)
2015-09-17 08:03:01.771 69275 ERROR barbican.api.controllers File "/Users/dmccowan/barbican/barbican/api/controllers/__init__.py", line 90, in enforcer
2015-09-17 08:03:01.771 69275 ERROR barbican.api.controllers return fn(inst, *args, **kwargs)
2015-09-17 08:03:01.771 69275 ERROR barbican.api.controllers TypeError: on_get() takes exactly 2 arguments (3 given)
2015-09-17 08:03:01.771 69275 ERROR barbican.api.controllers
2015-09-17 08:03:01.773 69275 INFO barbican.api.middleware.context [req-d4aed034-c754-4213-95eb-34690c2844cf aef5916109094125b7e52fdd7c43ecc2 0b0ea955139a4a0690a86f2d95310042 - default default] Processed request: 500 Internal Server Error - GET http://localhost:9311/v1/cas/23f269d1-2def-4ec7-8036-3b29c138ef45/foo
{address space usage: 2636541952 bytes/2514MB} {rss usage: 71565312 bytes/68MB} [pid: 69275|app: 0|req: 4/4] 127.0.0.1 () {28 vars in 1972 bytes} [Thu Sep 17 08:03:01 2015] GET /v1/cas/23f269d1-2def-4ec7-8036-3b29c138ef45/foo => generated 147 bytes in 8 msecs (HTTP/1.1 500) 4 headers in 191 bytes (2 switches on core 0)