Introduce non-expectation error ExampleFailed

Used by fail method.
Still todo: Output from failed example is missing because there are no 
expectations.

spec/spec_helper.cr

@@ -6,7 +6,7 @@ macro it_fails(description = nil, &block)
   it {{description}} do
     expect do
       {{block.body}}
-    end.to raise_error(Spectator::ExpectationFailed)
+    end.to raise_error(Spectator::ExampleFailed)
   end
 end
 

src/spectator/dsl/expectations.cr

@@ -12,7 +12,7 @@ module Spectator::DSL
     # Immediately fail the current test.
     # A reason can be specified with *message*.
     def fail(message = "Example failed", *, _file = __FILE__, _line = __LINE__)
-      raise ExpectationFailed.new(Location.new(_file, _line), message)
+      raise ExampleFailed.new(Location.new(_file, _line), message)
     end
 
     # Mark the current test as pending and immediately abort.

src/spectator/example_failed.cr

@@ -0,0 +1,14 @@
+require "./location"
+
+module Spectator
+  # Exception that indicates an example failed.
+  # When raised within a test, the test should abort.
+  class ExampleFailed < Exception
+    getter! location : Location
+
+    # Creates the exception.
+    def initialize(@location : Location?, message : String? = nil, cause : Exception? = nil)
+      super(message, cause)
+    end
+  end
+end

src/spectator/expectation_failed.cr

@@ -1,15 +1,16 @@
+require "./example_failed"
 require "./expectation"
 
 module Spectator
   # Exception that indicates an expectation from a test failed.
   # When raised within a test, the test should abort.
-  class ExpectationFailed < Exception
+  class ExpectationFailed < ExampleFailed
     # Expectation that failed.
     getter expectation : Expectation
 
     # Creates the exception.
     def initialize(@expectation : Expectation, message : String? = nil, cause : Exception? = nil)
-      super(message, cause)
+      super(expectation.location?, message, cause)
     end
   end
 end

src/spectator/harness.cr

@@ -1,4 +1,5 @@
 require "./error_result"
+require "./example_failed"
 require "./example_pending"
 require "./expectation"
 require "./mocks"
@@ -118,7 +119,7 @@ module Spectator
       case error
       when nil
         PassResult.new(elapsed, @expectations)
-      when ExpectationFailed
+      when ExampleFailed
         FailResult.new(elapsed, error, @expectations)
       when ExamplePending
         PendingResult.new(error.message || PendingResult::DEFAULT_REASON, elapsed, @expectations)