Update documentation to be consistent with return codes

Fixes #831

CHANGELOG.md

@@ -121,7 +121,7 @@ generate them, leading to client errors.
 MISC:
 
  * Various documentation fixes and improvements [GH-685] [GH-688] [GH-697]
-   [GH-710] [GH-715]
+   [GH-710] [GH-715] [GH-831]
 
 ## 0.3.1 (October 6, 2015)
 

api/SPEC.md

@@ -87,7 +87,7 @@ The following HTTP status codes are used throughout the API.
 - `200` - Success with data.
 - `204` - Success, no data returned.
 - `400` - Invalid request, missing or invalid data.
-- `401` - Unauthorized, your authentication details are either
+- `403` - Forbidden, your authentication details are either
    incorrect or you don't have access to this feature.
 - `404` - Invalid path. This can both mean that the path truly
    doesn't exist or that you don't have permission to view a

website/source/docs/http/index.html.md

@@ -133,7 +133,7 @@ The following HTTP status codes are used throughout the API.
 - `204` - Success, no data returned.
 - `400` - Invalid request, missing or invalid data. See the
    "validation" section for more details on the error response.
-- `401` - Unauthorized, your authentication details are either
+- `403` - Forbidden, your authentication details are either
    incorrect or you don't have access to this feature.
 - `404` - Invalid path. This can both mean that the path truly
    doesn't exist or that you don't have permission to view a