Insert example failed exception

src/spectator/example_failed.cr

@@ -0,0 +1,5 @@
+module Spectator
+  # Exception that indicates an example failed and should abort.
+  class ExampleFailed < Exception
+  end
+end

src/spectator/expectation_failed.cr

@@ -1,6 +1,8 @@
+require "./example_failed"
+
 module Spectator
   # Exception that indicates a required expectation was not met in an example.
-  class ExpectationFailed < Exception
+  class ExpectationFailed < ExampleFailed
     # Outcome of the expectation.
     # Additional information can be retrieved through this.
     getter result : Expectations::Expectation::Result

src/spectator/includes.cr

@@ -23,6 +23,7 @@ require "./example_group"
 require "./nested_example_group"
 require "./root_example_group"
 
+require "./example_failed"
 require "./expectation_failed"
 require "./test_results"
 require "./runner"