115 colinear points median

[radumg]

fixes #115 by implementing a co-linearity check for the points before making a convex hull.

The method

• works for both 2D and 3D
• see http://www.ambrsoft.com/MathCalc/Vector/Vector_.htm#cross for calculating cross-product of vectors

if points are colinear, return the midpoint of the line they form if not, do the convex hull

[radumg]

@SHKnudsen added tests for Core, in CoreTests, but they don't want to run for a reason, mind having a look ?

likely related to #117

[SHKnudsen]

@radumg seems like the issue with running the tests is related with this https://developercommunity.visualstudio.com/content/problem/579073/test-discovery-reporting-dlls-do-not-match.html

I updated VS to 16.2 and everything works for me now, can you check?