couchapp push fails since request 2.41.0

[cgreenhalgh]

couchapp 0.11.0 push fails on the second PUT; couchdb reports an 400 invalid_json.
This appears to be due to request 2.41.0+ mutating the headers object that is passed into each PUT request (specifically content-length is added). As the second request length is usually different to the first couchdb sees a truncated JSON object in the request body. See request issue 1060

[xp-lol-er]

Yes, i was struggling with this for the last days, I finally fixed it by having an explicit dependency on requrest@2.40.0.