fix(travis): Pin to 2.0.0-dev.17.0 SDK.
fix(travis): Pin to 2.0.0-dev.17.0 SDK.

We can revert this after dart-lang/sdk#31940 is fixed.

Temporary workaround for #789

PiperOrigin-RevId: 182429134

matanlurey/angular,chalin/angular2,kevmoo/angular,angulardart/angular,kevmoo/angular,matanlurey/angular,chalin/angular2,chalin/angular2,angulardart/angular,kevmoo/angular,matanlurey/angular,angulardart/angular