`QuotaRoleAllocateNonQuotaResource` is failing.

[ RUN      ] HierarchicalAllocatorTest.QuotaRoleAllocateNonQuotaResource
../../src/tests/hierarchical_allocator_tests.cpp:4094: Failure
Value of: allocations.get().isPending()
  Actual: false
Expected: true
[  FAILED  ] HierarchicalAllocatorTest.QuotaRoleAllocateNonQuotaResource (12 ms)

The test is failing because:

After agent3 is added, it misses a settle call where the allocation of agent3 is racy.
In addition, after https://github.com/apache/mesos/commit/7df8cc6b79e294c075de09f1de4b31a2b88423c8
we now offer nonquota resources on an agent (even that means "chopping") on top of role's satisfied guarantees, the test needs to be updated in accordance with the behavior change.