chore(travis): override default task
chore(travis): override default task

Travis will run `npm test` by default, and I tried augmenting it with
the `after_script` option. But for some reason it couldn’t connect to
Sauce Labs and when that failed it didn’t fail the build.

Ref: https://travis-ci.org/seriema/angular-apimock/builds/74544335
Note: that commit isn’t what caused the issue, I just waited too long
to sync to GitHub so Travis triggered later. The real issue got
introduced in 10ca94b.

seriema/angular-apimock,MartinSandstrom/angular-apimock,MartinSandstrom/angular-apimock,seriema/angular-apimock