composer.json update for compability problem with bootstrap 4

[bobonov]

The blueimp < 10.0.4 is not compatible with boootstrap 4
blueimp/jQuery-File-Upload#3537
The composer.json should be changed to allow a more recent version of the plugin
Also the bootstrap dependency should be managed accordingly to the blueimp version
Another request is to remove the gallery dependency since not every project need it.