peerDependency range should include newly released sinon@10

[AviVahl]

sinon@10.0.0 is out.t sinon-chai gets a peerDependency warning:
warning " > sinon-chai@3.5.0" has incorrect peer dependency "sinon@>=4.0.0 <10.0.0".

FYI @domenic

[simondel]

Thanks for letting me know! I've released version 3.6.0 to fix this.