Fixing installation with dbal (#552) and PHP 7.4 (#554)

[Tchekda]

During installation I encountered some problems due librairy updates that broke compatibility.

• I just forced doctrine/dbal not to use higher version than 2.10.0. by setting the compatibility at <2.10.0 : "Whoops, looks like something went wrong." when finishing setup #552 : Migrating a varchar to a bigint causes invalid charset instructions to appear laravel/framework#30539
• I also forced the PHP version to 7.3 because the is a backwards incompatible change in 7.4', so I've set <7.5` : PHP7.4: ErrorException: Trying to access array offset on value of type int [Solution] #554 https://stackoverflow.com/a/60413095

Feel free to tell me what to change to make this PR accepted.

[Tchekda]

I've also juste updated your travis file so the tests goes green on PHP 7.3, previous versions aren't supported anymore

[pozzo-balbi]

Hi, installed php 7.4 and I got installation error. Changed doctrine/dbal to < 2.10 and php to 7.3 and no problem with installation.

@Tchekda Thanks!

[rafzei]

Thanks for this PR. I've just got this issue during installation.

[Tchekda]

Maybe another day I will take time to update the whole project to latest versions of laravel and dbal, but for now this fix is working like a charm

[matthewdm0816]

Same issue and you PR does fix the case, Thanks!

[hy2prc]

@Tchekda Solved. Thank you.

[matheusgontijo]

Thank you so much @Tchekda. Your modifications made the installation to work. Thanks for the clarification and your time.

[Teeis]

Hi, installed php 7.4 and I got installation error. Changed doctrine/dbal to < 2.10 and php to 7.3 and no problem with installatio

As said above, I solved my problem, thank you