caldb add does not warn when trying to add an unsupported file

[KathleenLabrie]

When trying to caldb add a user BPM, nothing happens. caldb add does not add the user BPM. This is good, that is the desired behavior (I have evidence that it is the desired behavior and this is not the point of this ticket). The issue is that it should warn the user that it did not add it because it isn't a recognized calibration.

There's a BPM, produced with NIRI's makeProcessedBPM here:
https://drive.google.com/drive/folders/1ByrpK3NlPgfBchraFbUKYW0SAU_s3FVP?usp=sharing

Set up a calibration DB in dragonsrc and init it. Then:

$ caldb add N20160102S0373_bpm.fits
$ caldb list

It has not added it, good. But it has not complained about it either, bad.

I would expect a warning along the lines of: "WARNING: N20160102S0373_bpm.fits is not a recognized calibration, not addind to the calibration database."