remove causes

[cbizon]

We frequently return a bunch of merges for things like "causes vomiting", 'causes nausea', etc. So you are finding things out about side effect profiles. They're correct, I guess, but not super useful.... do we take them out?

[cbizon]

If the result merging were better, this wouldn't matter so much, but for instance, we get this result for merging "treats Autism" https://arax.ncats.io/?r=c71ed7fd-e9dc-41ed-8c17-074bcba400a4. So many new answers that don't say very much.