[v2] Breaking changes - support only recent-ish Laravel versions (6+)

[tabacitu]

I haven't been able to give this repo the attention it deserves. Maybe it's time to fix that. Let's at least close all the issues we can, and merge all PRs that make sense.

So far:

• fix issue #144 #165 Use bigInteger by default on pivot tables - fixes Foreign key doesn't work correctly with id #144; here's why;
• drop support for Laravel under version 5.8 and lower - 5e8bfbb;
• dumpautoload after creating Model dumpAutoloads after creating Model [Fixes #157] #158;
• write migration name in command prompt after creation Changed make:migration:schema message to behave like make:migration #126;
• by default no model is created, you have to specify --model=true to create one - 67dc4dc;
• ability to specify --path=smth to change where migrations are generated Optional path parameter for new migrations #90 ;
• prevented situation where two migrations were generated, one by this package and one by Laravel's make:model command; Fixed duplicate migration generation issue by passing --no-migration fixes #40 #43 ; fixes 2 migrations files are generated on php artisan make:migration:schema. #40 ;

To do: see the v2 board.

[tabacitu]

Ok so... it looks like I've overestimated how much time I can devote to this package 😄

I've just polished everything up, so the features we do have right now and are confirmed, are tested and working fine. And after looking at the v2 Project again I've concluded that it's best to just go ahead and launch v2 as it is. Most issues & features there can be added as non-breaking changes, no problem.

So... I'm going to release this right away.