tests: Trim .nim files trailing whitespace

via OSX: find . -name '*.nim' -exec sed -i '' -E 's/[[:space:]]+$//' {} +

tests/array/tarrayplus.nim

@@ -6,7 +6,7 @@ proc `+`*[R, T] (v1, v2: array[R, T]): array[R, T] =
   for i in low(v1)..high(v1):
     result[i] = v1[i] + v2[i]
 
-var 
+var
   v1: array[0..2, float] = [3.0, 1.2, 3.0]
   v2: array[0..1, float] = [2.0, 1.0]
   v3 = v1 + v2