AffineTransform multiplication test failed once

From: https://travis-ci.org/jlfwong/speedscope/builds/416911664?utm_source=github_status&utm_medium=notification

```
FAIL src/lib/math.test.ts (42.845s)
● AffineTransform › times
Failed after 62 tests and 55 shrinks. rngState: 8394d7fb8c61ae2305; Counterexample: {"m00":0,"m01":-5.367341258943892e-7,"m02":0,"m10":-5.637762076626807e-7,"m11":22.105444583576173,"m12":0}; {"m00":-19.956948631443083,"m01":41.27141907811165,"m02":32.4375735828653,"m10":-19.53049001749605,"m11":40.38256627973169,"m12":3.136250004172325};
359 |
360 | test('times', () => {
> 361 | jsc.assertForall(invertibleTransform, invertibleTransform, (t1, t2) => {
| ^
362 | return t1
363 | .times(t2)
364 | .times(t2.inverted()!)
at node_modules/jsverify/lib/jsverify.js:360:15
at Object.map (node_modules/jsverify/lib/functor.js:35:12)
at checkThrow (node_modules/jsverify/lib/jsverify.js:354:30)
at Object.assertForall (node_modules/jsverify/lib/jsverify.js:485:10)
at Object.test (src/lib/math.test.ts:361:9)
```