Update tarteaucitron library to version 1.20.0 when released

Wouldn't it make sense to use a Composer constraint like ^1.20.1?
This way we don't have to update the module every time a new release of tarteaucitron is published.

People are still free to upgrade the TarteAuCitron library as they wish.

I'm just a bit scared that some TarteAuCitron release will break the TacJS module.

But may be we could try to loosen the version requirement and see how it goes.

What do you think?

Updated the version requirement to ~1.20 for now.

I guess using ~ would be an acceptable compromise.