Update spec/middleware/metrics_spec.rb

Co-authored-by: Troels Thomsen <[email protected]>

Author: beanieboi

spec/middleware/metrics_spec.rb

@@ -59,7 +59,7 @@ def app
   it "measures the request latency" do
     expect(Pliny::Metrics).to receive(:measure) do |key, opts|
       assert_equal(key, "requests.latency")
-      assert(opts[:value] > 4 && opts[:value] < 6)
+      assert_in_delta(5, opts[:value], 1)
     end
 
     get "/hello"