Return 404 if course section doesn't exist in Amaint

Now that we are planning to delete sections that have been deleted in SIMS/Amaint, need to fix the API to return 404 when section give is not in the output from the SFU REST server.
Fix loop to make it work for non "*00" sections (e.g. d101, d110, g001)
Merge pull request #156 from ronvs/fix-sfu-amaint-course-api

Return 404 if course section doesn't exist in Amaint