Feat: adding some basic music theory

tests/forth/randomness.rs

@@ -171,3 +171,8 @@ fn logrand_requires_positive() {
     expect_error("-1.0 10.0 logrand", "logrand requires positive values");
     expect_error("1.0 0.0 logrand", "logrand requires positive values");
 }
+
+#[test]
+fn rand_equal_bounds() {
+    expect_float("5.0 5.0 rand", 5.0);
+}