autobahn websocket test suite tracking

To ensure that actix-web provides production-grade websockets, it should pass the crossbar autobahn test suite.

https://github.com/crossbario/autobahn-testsuite

Currently failing cases:

- [x] 3.1 - Issue #1579, PR #xx
- [ ] 3.2
- [ ] 3.3
- [ ] 3.4
- [ ] 3.5
- [ ] 3.6
- [x] 5.3–5.8 - fixed in https://github.com/actix/examples/commit/561d76830413e906f19944ad78fceddde37cc889
- [x] 5.18 - fixed by #4219
- [x] 5.19—5.20 - fixed in https://github.com/actix/examples/commit/561d76830413e906f19944ad78fceddde37cc889
- [x] 6.1.2—6.1.3 - fixed in https://github.com/actix/examples/commit/561d76830413e906f19944ad78fceddde37cc889
- [x] 6.2.2—6.2.4 - fixed in https://github.com/actix/examples/commit/561d76830413e906f19944ad78fceddde37cc889
- [x] 6.3.2 - fixed in https://github.com/actix/examples/commit/561d76830413e906f19944ad78fceddde37cc889
- [ ] 6.4.1
- [ ] 6.4.2
- [ ] 6.4.3
- [ ] 6.4.4
- [x] 7.1.3—7.1.4 - user dependent: closed in actix/examples#335
- [x] 7.9.1–7.9.9 - fixed by #4218
- [x] 9.x.x - fixed in https://github.com/actix/examples/commit/36d5d4f18896be9732bf937ceadc2be552589906
- [x] 10.1.1 - fixed in https://github.com/actix/examples/commit/561d76830413e906f19944ad78fceddde37cc889