Fix box configuration to work with humbug/box

[jawngee]

With regards to #1520:

Considering humbug/box (https://github.com/humbug/box) is now the actively maintained app for building phars, I updated the box.json configuration so that working phars can be generated.

The existing box.json was not working at all as humbug/box excludes composer.json from the root unless you explicitly set a flag to tell it not to.

[codecov]

Codecov Report

Merging #1522 into master will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master    #1522   +/-   ##
=========================================
  Coverage     74.44%   74.44%           
  Complexity     1976     1976           
=========================================
  Files            54       54           
  Lines          5826     5826           
=========================================
  Hits           4337     4337           
  Misses         1489     1489

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[lorenzo]

Thanks!

[lorenzo]

What do you suggest our next step should be?

[theofidry]

Hello, just saw this issue after a report from a user:

• There is some instructions to install phinx somewhere still referencing Box2
• It is not clear where/how box is downloaded which makes confusing which Box version this configuration is used with
• If you are running the latests versions of Box3, you should have a couple of recommendations regarding redundant configuration settings and you could probably trim it down even further by taking advantage of some new Box3 features, namely that most files can be inferred from the composer.json file