Capture elapsed test time

src/spectator/errored_example_result.cr

@@ -7,8 +7,5 @@ module Spectator
     def errored? : Bool
       true
     end
-
-    def initialize(@example, @error)
-    end
   end
 end

src/spectator/example_result.cr

@@ -1,10 +1,11 @@
 module Spectator
   abstract class ExampleResult
     getter example : Example
+    getter elapsed : Time::Span
 
     abstract def passed? : Bool
 
-    protected def initialize(@example)
+    protected def initialize(@example, @elapsed)
     end
   end
 end

src/spectator/failed_example_result.cr

@@ -8,7 +8,8 @@ module Spectator
       false
     end
 
-    def initialize(@example, @error)
+    def initialize(example, elapsed, @error)
+      super(example, elapsed)
     end
   end
 end

src/spectator/runner.cr

@@ -23,12 +23,24 @@ module Spectator
     end
 
     private def run_example(example)
-      example.run
-      SuccessfulExampleResult.new(example)
-    rescue failure : ExpectationFailedError
-      FailedExampleResult.new(example, failure)
-    rescue ex
-      ErroredExampleResult.new(example, ex)
+      error = nil
+      elapsed = Time.measure do
+        begin
+          example.run
+        rescue failure : ExpectationFailedError
+          error = failure
+        rescue ex
+          error = ex
+        end
+      end
+      case error
+      when Nil
+        SuccessfulExampleResult.new(example, elapsed)
+      when ExpectationFailedError
+        FailedExampleResult.new(example, elapsed, error)
+      else
+        ErroredExampleResult.new(example, elapsed, error)
+      end
     end
   end
 end