Add test file.

test/models/PLY/points.ply

@@ -0,0 +1,17 @@
+ply
+format ascii 1.0
+element vertex 4
+property float x
+property float y
+property float z
+property uchar red
+property uchar green
+property uchar blue
+property float nx
+property float ny
+property float nz
+end_header
+0.0 0.0 0.0 255 255 255 0.0 1.0 0.0
+0.0 0.0 1.0 255 0 255 0.0 0.0 1.0
+0.0 1.0 0.0 255 255 0 1.0 0.0 0.0
+0.0 1.0 1.0 0 255 255 1.0 1.0 0.0