[5.4] Make SessionGuard Macroable

[calebporzio]

I often find it convenient to shortcut code like:

auth()->user()->company

By adding "Macroable" to the SessionGuard, we open up possibilities for things like:

auth()->company

[antonkomarev]

@calebporzio thats awesome!

[calebporzio]

Ya, isn't that fun? all sorts of nice conveniences can come of this.

[antonkomarev]

It looks like all Laravel classes will be Macroable soon and it will be rebranded to Macrolavel :}

[m1guelpf]

@a-komarev It helps developers extend Laravel functionality... so it's normal everything is Macroable

[calebporzio]

@a-komarev one day... one day...