Expand Substitution Matching Types support

Add substitution support for `Symbol` and `Numeric`. It can be
convenient to pass in the value of an `ActiveRecord::Base#id`, or a
`Symbol` declared elsewhere in the test.

Author: seanpdoyle

lib/rails/dom/testing/assertions/selector_assertions/substitution_context.rb

@@ -28,6 +28,6 @@ def matcher_for(value, format_for_presentation)
     end
 
     def substitutable?(value)
-      value.is_a?(String) || value.is_a?(Regexp)
+      [ Symbol, Numeric, String, Regexp ].any? { |type| value.is_a? type }
     end
 end

test/selector_assertions_test.rb

@@ -135,6 +135,16 @@ def test_substitution_values
     end
   end
 
+  def test_substitution_values_with_values_other_than_string_or_regexp
+    render_html %Q{<div id="id_string">symbol</div><div id="1">numeric</div>}
+    assert_select "div:match('id', ?)", :id_string do |elements|
+      assert_equal 1, elements.size
+    end
+    assert_select "div:match('id', ?)", 1 do |elements|
+      assert_equal 1, elements.size
+    end
+  end
+
   def test_assert_select_root_html
     render_html '<a></a>'