refactor(@angular/cli): remove deprecated karma builder `environment` schema option
refactor(@angular/cli): remove deprecated karma builder `environment` schema option

clydin/angular-cli,ocombe/angular-cli,Brocco/angular-cli,ocombe/angular-cli,Brocco/angular-cli,angular/angular-cli,catull/angular-cli,angular/angular-cli,catull/angular-cli,geofffilippi/angular-cli,angular/angular-cli,ocombe/angular-cli,geofffilippi/angular-cli,clydin/angular-cli,Brocco/angular-cli,Brocco/angular-cli,clydin/angular-cli,Brocco/angular-cli,ocombe/angular-cli,ocombe/angular-cli,clydin/angular-cli,catull/angular-cli,geofffilippi/angular-cli,catull/angular-cli,geofffilippi/angular-cli,angular/angular-cli