Accept username as valid author name in CHANGELOG

This fixes the `CHANGELOG` linter to accept usernames that include
digits as valid author names.

Author: jonathanhefner

tools/rail_inspector/lib/rail_inspector/changelog.rb

@@ -39,7 +39,7 @@ def validate_authors
           return if no_changes?
 
           authors =
-            lines.reverse.find { |line| line.match?(/\*[^\d\s]+(\s[^\d\s]+)*\*/) }
+            lines.reverse.find { |line| line.match?(/^ *\*[^*\s].*[^*\s]\*$/) }
 
           return if authors
 

tools/rail_inspector/test/rail_inspector/changelog_test.rb

@@ -18,6 +18,14 @@ def test_entries_without_author_are_invalid
     assert_equal 2, offenses.length
   end
 
+  def test_valid_username_is_valid_author
+    assert_valid_entry <<~CHANGELOG
+      *   Cool change.
+
+          *1337-rails-c0d3r*
+    CHANGELOG
+  end
+
   def test_parses_with_extra_newlines
     @changelog = changelog_fixture("action_mailbox_83d85b2.md")
 
@@ -126,6 +134,11 @@ def offenses
       entries.flat_map(&:offenses)
     end
 
+    def assert_valid_entry(source)
+      entry = RailInspector::Changelog::Entry.new(source.lines(chomp: true), 1)
+      assert_empty entry.offenses, "Entry has offenses"
+    end
+
     ANNOTATION_PATTERN = /\s*\^+ /
 
     def assert_offense(source)