Replace continue with continue 2 within switch PHP 7.3

[daniel-de-wit]

Fixes #10

[coveralls]

Coverage increased (+0.0004%) to 99.333% when pulling e6d06b7 on daniel-de-wit:master into 0363132 on czim:master.

[coveralls]

Coverage remained the same at 99.332% when pulling fe53d91 on daniel-de-wit:master into 0363132 on czim:master.

[czim]

Funny story: I was actually under the incorrect impression that continue behaved in the C-like way!
Hence my use of it. If I wanted break behaviour here, I would've preferred using that instead.

So though it did not matter here, this was a bug waiting to happen. All thanks to PHP-weirdness. Useful and interesting to learn :D