test: add filter, seed and better diff checking to test script
test: add filter, seed and better diff checking to test script

It wasnt checking the staging area. It also now shows the packages that will be
tested.

Filter and Seed are arguments that are directly passed to Jasmine. They can be
used to reproduce tests.

filipesilva/angular-cli,Brocco/angular-cli,geofffilippi/angular-cli,beeman/angular-cli,catull/angular-cli,manekinekko/angular-cli,angular/angular-cli,hansl/angular-cli,geofffilippi/angular-cli,ocombe/angular-cli,catull/angular-cli,clydin/angular-cli,DevIntent/angular-cli,DevIntent/angular-cli,geofffilippi/angular-cli,DevIntent/angular-cli,beeman/angular-cli,ocombe/angular-cli,catull/angular-cli,DevIntent/angular-cli,manekinekko/angular-cli,clydin/angular-cli,angular/angular-cli,beeman/angular-cli,ocombe/angular-cli,angular/angular-cli,hansl/angular-cli,ocombe/angular-cli,Brocco/angular-cli,Brocco/angular-cli,hansl/angular-cli,angular/angular-cli,filipesilva/angular-cli,ocombe/angular-cli,Brocco/angular-cli,hansl/angular-cli,beeman/angular-cli,filipesilva/angular-cli,geofffilippi/angular-cli,manekinekko/angular-cli,filipesilva/angular-cli,DevIntent/angular-cli,Brocco/angular-cli,clydin/angular-cli,catull/angular-cli,clydin/angular-cli