Detect “No preview available” when generating thumbs

[andylolz]

I wonder if phantom.js could spot “No preview available”, and avoid generating a thumbnail. This would potentially be really handy:

1. Without a thumbnail, the document won’t be displayed in recent CVs / on the frontpage / in the og:image for the homepage / on @democlubCVs
2. We could get the cron to email us that something’s broken

[frabcus]

I reckon it can just look for the text `No preview available

[frabcus]

@andylolz think I've fixed this! I've deployed to mpcv app. Do you have cron running from any other apps?

[andylolz]

nope

[andylolz]

This looks much nicer than my solution (filecmp.cmp() with a “No preview available” image in the repo!)