Fixes GH-69. Any api with `/doc` was failing.

The problem is that the documentation controller was keying off the last
index of `/doc` which causes issues if you have any api's that have that
path.

So, the fix is to look for the first index of `/doc/`.

Signed-off-by: Nick Campbell <nicholas.j.campbell@gmail.com>
Merge pull request #85 from ncb000gt/master

Fixes GH-69. Any api with `/doc` was failing.