changed placement id to be string instead of int (#988)
changed placement id to be string instead of int (#988)

* changed placement id to be string instead of int

* Update undertone.md

prebid/prebid.github.io,sonobi/prebid.github.io,prebid/prebid.github.io,sonobi/prebid.github.io,sonobi/prebid.github.io,prebid/prebid.github.io