Separate non-documentation tests from the code

source/tanya/math/package.d

@@ -12,7 +12,7 @@
  * be found in its submodules. $(D_PSYMBOL tanya.math) doesn't import any
  * submodules publically, they should be imported explicitly.
  *
- * Copyright: Eugene Wissner 2016-2018.
+ * Copyright: Eugene Wissner 2016-2019.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
  * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
@@ -21,7 +21,6 @@
  */
 module tanya.math;
 
-import tanya.algorithm.mutation;
 import tanya.math.mp;
 import tanya.math.nbtheory;
 import tanya.meta.trait;