Add dev-master branch alias to composer.json

[fprochazka]

This change allows me to require ~2.4.0@dev and the users of my integration of this lib will get stable version 2.4.*, but when developing, my builds will be done agains master branch of this library, which means I'll know about every compatibility break, or behaviour change, even before you tag the library, allowing me to act on them even before the target user's app might get broken.

The only think I'm not sure about is, that where the alias should be 2.4-dev or 2.5-dev. I would appreciate feedback from somebody more skilled with composer.

[fprochazka]

I've investigated a bit and it seems that the best practice is to have the same "feature version" as you have on the branch you're aliasing. Which means if your last tag on master is 2.4, then you should have branch alias 2.4-dev, when you tag 2.4.1 nothing changes, and when you tag 2.5.0, you should bump the branch alias to 2.5-dev

[fprochazka]

Ping @videlalvaro, is there any problem? Can you please either merge this or tag 2.4.1? Or you can do both, I won't mind :)

[TomasVotruba]

Ping @videlalvaro pls

[TomasVotruba]

Thank you!

[fprochazka]

@videlalvaro thank you!