fix node v0.6.x test failures
fix node v0.6.x test failures

kartotherian/kartotherian,nyurik/kartotherian,kartotherian/kartotherian,jaredbrookswhite/tilelive-vector,kartotherian/kartotherian,mapbox/tilelive-vector,nyurik/kartotherian,nyurik/tilelive-vector,nyurik/kartotherian,kartotherian/kartotherian,nyurik/kartotherian