`degreesToDistance` different for Latitude and Longitude

Looking at @turf/helpers distanceToRadians and distanceToDegrees methods I noticed that if you move a point E-W or N-S of the same amount of degrees and calculate the distance between the original point and the moved point, you actually get two different distances. Is that for some reason correct? If so, why? Then, how could you create for example a square from a point' that actually looks like a square? Using @turf/bearing`, due to #681, at 90˚ the end points are not at the same latitude, while varying the coordinates you don’t get a square:

I added also some test on @turf/helpers to highlight the issue.

[stebogit]

@guanzo if you have just a point you can use @turf/destination

var pt = turf.point([lng, lat]); // note the order
var destinationPoint = turf.destination(pt, 1, yourDirectionAngle, 'miles');

[DenisCarriere]

@stebogit I’m 👍 with the method renaming, pretty sure these methods are only used internally. We can include these changes in v5.0 and update the earthRadiusIn factor at the same time.