Report failed expectation line

In output listing the failures, the comment line now shows the failed expectation line.
Previously this showed the example's source line.

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+### Changed
+- Source line reported by failure list changed to line containing `expect` instead of example start line.
+
 ## [0.10.3] - 2021-10-13
 ### Fixed
 - Fixed runtime error with `expect` outside of test block - now gives compilation error.
@@ -358,6 +362,7 @@ This has been changed so that it compiles and raises an error at runtime with a
 First version ready for public use.
 
 
+[Unreleased]: https://gitlab.com/arctic-fox/spectator/-/compare/v0.10.3...master
 [0.10.3]: https://gitlab.com/arctic-fox/spectator/-/compare/v0.10.2...v0.10.3
 [0.10.2]: https://gitlab.com/arctic-fox/spectator/-/compare/v0.10.1...v0.10.2
 [0.10.1]: https://gitlab.com/arctic-fox/spectator/-/compare/v0.10.0...v0.10.1

src/spectator/formatting/components/fail_result_block.cr

@@ -45,5 +45,13 @@ module Spectator::Formatting::Components
         io << padding << key.colorize(:red) << ": ".colorize(:red) << value
       end
     end
+
+    # Produces the location line.
+    # This is where the result was determined.
+    private def location_line(io)
+      return unless location = @expectation.location? || @example.location?
+
+      line(io) { io << Comment.colorize(location) }
+    end
   end
 end