Looking at the examples for Node and PHP, those are essentially two different request libs with the same name. That lack of consistency is a problem - at the very least anyone thinking "porting this app to <language> will be easy because Unirest is available" will be in for a nasty surprise. At worst, it shows a lack of planning and a lack of communication within the Unirest team, and that's a very big problem for anyone relying on the code.
Moving forward, I'd recommend working very hard on unifying your featureset and API so it's consistent across all the versions.
Moving forward, I'd recommend working very hard on unifying your featureset and API so it's consistent across all the versions.