[omus]

Follow up to #137

With this PR the timing is captured:

julia> using TestReports, Test, Dates
[ Info: Precompiling TestReports [dcd651b4-b50a-5b6b-8f22-87e9f253a252] (caches not reused: 1 for file size changed, 1 for different source file path)
Precompiling TestReports finished.
  1 dependency successfully precompiled in 1 seconds. 37 already precompiled.

julia> @testset ReportingTestSet "MyTests" begin
           record_testset_property("ID", 1)
           @testset "inner" begin
              @test 2 == 2
              sleep(3)
              @test 3 == 3
           end
       end;
Test Summary: | Pass  Total  Time
inner         |    2      2  3.2s

With just #137 the output was:

Test Summary: | Pass  Total  Time
inner         |    2      2  0.0s