GET /version returns 200 when version doc is missing

[kofalt]

Another in the category of "API responds success in failure state" problems.

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---- BEGIN HTTP ----
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GET /api/version HTTP/1.1
Host: docker.local.flywheel.io:8443
User-Agent: Flywheel SDK
Authorization: scitran-user 11652
Accept-Encoding: gzip


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-- BEGIN RESPONSE --
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HTTP/1.1 200 OK
Cache-Control: no-cache
Connection: keep-alive
Content-Type: text/html; charset=utf-8
Date: Mon, 31 Jul 2017 16:40:57 GMT
Expires: Mon, 31 Jul 2017 16:40:56 GMT
Server: nginx/1.9.3
Content-Length: 0


--------------------
----- END HTTP -----
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