Make time based tests less likely to fail non-deterministically

These tests deal with real durations of time, and can fail due to GC or
other performance impacting events.  Increase the time scales slightly
to make them less prone for sporadic failure.

test/new_relic/agent/transaction_sampler_test.rb

@@ -756,17 +756,17 @@ def test_harvest_slowest
     slowest = @sampler.harvest(nil, 0)[0]
     assert((slowest.duration >= 0.09), "expected sample duration >= 0.09, but was: #{slowest.duration.inspect}")
     # this assert is here to make sure the test remains valid
-    assert((slowest.duration <= 0.15), "expected sample duration <= 0.15, but was: #{slowest.duration.inspect}")
+    assert((slowest.duration <= 0.2), "expected sample duration <= 0.15, but was: #{slowest.duration.inspect}")
 
 
     run_sample_trace { sleep 0.0001 }
     not_as_slow = @sampler.harvest(slowest, 0)[0]
     assert((not_as_slow == slowest), "Should re-harvest the same transaction since it should be slower than the new transaction - expected #{slowest.inspect} but got #{not_as_slow.inspect}")
 
-    run_sample_trace { sleep 0.16 }
+    run_sample_trace { sleep 0.25 }
     new_slowest = @sampler.harvest(slowest, 0)[0]
     assert((new_slowest != slowest), "Should not harvest the same trace since the new one should be slower")
-    assert((new_slowest.duration >= 0.15), "Slowest duration must be >= 0.15, but was: #{new_slowest.duration.inspect}")
+    assert((new_slowest.duration >= 0.2), "Slowest duration must be >= 0.15, but was: #{new_slowest.duration.inspect}")
   end
 
   def test_prepare_to_send

test/new_relic/agent/worker_loop_test.rb

@@ -23,15 +23,15 @@ def test_density
     # This shows how the tasks stay aligned with the period and don't drift.
     count = 0
     start = Time.now
-    @worker_loop.run(0.01) do
+    @worker_loop.run(0.03) do
       count +=1
       if count == 3
         @worker_loop.stop
         next
       end
     end
     elapsed = Time.now - start
-    assert_in_delta 0.03, elapsed, 0.02
+    assert_in_delta 0.09, elapsed, 0.02
   end
   def test_task_error__standard
     @logger.expects(:debug)