Update example for auth.json in BitBucket config
Update example for auth.json in BitBucket config

Remove the `config` level
andrerom/composer,vdm-io/composer,alcohol/composer,localheinz/composer,nicolas-grekas/composer,naderman/composer,slbmeh/composer,stof/composer,floverdevel/composer,fabpot/composer,staabm/composer,stefangr/composer,composer/composer,pierredup/composer,milleruk/composer,johnstevenson/composer