Added new RandomRangedGenerator test using PLINQ for thread safety testing.
Removed original slower RandomRangedGenerator async test
Changed test  to use Assert.DoesNotThrow instead of try-catch
Parameterized test, changed name back to original name.  Changed assert back to try-catch.
Removed try-catch from test so AggregateException will now bubble up to test runner.
Merge branch '227-randomrangedgeneratortest-performance' of https://github.com/dlongest/AutoFixture into dlongest-227-randomrangedgeneratortest-performance