The CI should catch warnings

[bobzhang]

/Users/hongbozhang/git/core/array/array.mbt:626:13-626:14 Warning 013: The type of this expression is (Array[_/0], Array[_/0]) -> Array[_/0], which contains unresolved type variables. The type variable is default to Unit.
/Users/hongbozhang/git/core/array/array.mbt:626:13-626:14 Warning 013: The type of this expression is (Array[_/0], Array[_/0]) -> Array[_/0], which contains unresolved type variables. The type variable is default to Unit.
/Users/hongbozhang/git/core/vec/vec.mbt:190:18-190:19 Warning 013: The type of this expression is (Vec[_/0], Vec[_/0]) -> Vec[_/0], which contains unresolved type variables. The type variable is default to Unit.
/Users/hongbozhang/git/core/vec/vec.mbt:190:18-190:19 Warning 013: The type of this expression is (Vec[_/0], Vec[_/0]) -> Vec[_/0], which contains unresolved type variables. The type variable is default to Unit.
Total tests: 376, passed: 376, failed: 0.