Show random seed

Only works when a seed specified, not when a random seed is used.

src/spectator/formatting/random_seed_text.cr

@@ -0,0 +1,14 @@
+module Spectator::Formatting
+  # Text displayed when using a random seed.
+  private struct RandomSeedText
+    # Creates the text object.
+    def initialize(@seed : UInt64)
+    end
+
+    # Appends the command to the output.
+    def to_s(io)
+      io << "Randomized with seed "
+      io << @seed
+    end
+  end
+end

src/spectator/formatting/suite_summary.cr

@@ -49,6 +49,9 @@ module Spectator::Formatting
     private def stats(report)
       @io.puts Runtime.new(report.runtime)
       @io.puts StatsCounter.new(report).color
+      if (seed = report.random_seed?)
+        @io.puts RandomSeedText.new(seed)
+      end
     end
 
     # Produces the skipped tests text if fail-fast is enabled and tests were omitted.