Increase the comparison precision in the tests

tests/lib.rs

@@ -7,12 +7,12 @@ mod fixtures;
 fn forward() {
     let mut data = fixtures::TIME_DATA.to_vec();
     fft::forward(&mut data);
-    assert::close(&data, &fixtures::FREQUENCY_DATA[..], 1e-13);
+    assert::close(&data, &fixtures::FREQUENCY_DATA[..], 1e-14);
 }
 
 #[test]
 fn inverse() {
     let mut data = fixtures::FREQUENCY_DATA.to_vec();
     fft::inverse(&mut data, true);
-    assert::close(&data, &fixtures::TIME_DATA[..], 1e-13);
+    assert::close(&data, &fixtures::TIME_DATA[..], 1e-14);
 }