Try to fix CircleCI failing (#252)

Author: jmh530

source/mir/ndslice/sorting.d

@@ -708,7 +708,9 @@ template setPivotAt(alias less = "a < b") {
 version(mir_test_topN)
 @safe pure
 unittest {
+ import mir.ndslice.slice: sliced;
  import mir.functional: naryFun;
+
  auto x = [3, 1, 5, 2, 0].sliced;
 
  auto y = setPivotAt!(naryFun!("a < b"))(x);
@@ -849,6 +851,8 @@ void topNImpl(alias less, alias pivotFunction, Iterator, SliceKind kind)(
 version(mir_test_topN)
 @safe pure
 unittest {
+ import mir.ndslice.slice: sliced;
+
  size_t nth = 2;
  auto x = [3, 1, 5, 2, 0].sliced;
  x.topN(nth);
@@ -859,6 +863,8 @@ unittest {
 version(mir_test_topN)
 @safe pure
 unittest {
+ import mir.ndslice.slice: sliced;
+
  size_t nth = 4;
  auto x = [3, 1, 5, 2, 0, 7].sliced(3, 2);
  x.topN(nth);
@@ -869,6 +875,8 @@ unittest {
 version(mir_test_topN)
 @safe pure
 unittest {
+ import mir.ndslice.slice: sliced;
+
  size_t nth = 2;
  auto x = [3, 1, 5, 2, 0].sliced;
  x.topN!("a > b")(nth);
@@ -879,6 +887,8 @@ unittest {
 version(mir_test_topN)
 @safe pure
 unittest {
+ import mir.ndslice.slice: sliced, Slice, SliceKind;
+ 
  static auto tail(Iterator, SliceKind kind)(Slice!(Iterator, 1, kind) slice) {
  return slice.length - 1;
  }
@@ -893,6 +903,7 @@ version(unittest) {
  template checkTopNAll(alias less = "a < b", alias pivotFunction = setPivotAt)
  {
  import mir.functional: naryFun;
+ import mir.ndslice.slice: SliceKind, Slice;
 
  static if (__traits(isSame, naryFun!less, less))
  {
@@ -926,6 +937,8 @@ version(unittest) {
 version(mir_test_topN)
 @safe pure
 unittest {
+ import mir.ndslice.slice: sliced;
+
  assert(checkTopNAll([2, 2].sliced));
 
  assert(checkTopNAll([3, 1, 5, 2, 0].sliced));