[API] Test Runner: Consider Integer keys for get Cached values

Author: picandocodigo

elasticsearch-api/api-spec-testing/test_file/test.rb

@@ -182,7 +182,7 @@ def get_cached_value(key)
             key =~ /^\$/ ? @cached_values.fetch(key.gsub(/[\$\{\}]/, ''), key) : key
           when Hash
             key.inject({}) do |hash, (k, v)|
-              k = k.to_s if k.is_a?(Float)
+              k = k.to_s if [Float, Integer].include? k.class
               if v.is_a?(String)
                 hash.merge(@cached_values.fetch(k.gsub(/[\$\{\}]/, ''), k) => @cached_values.fetch(v.gsub(/[\$\{\}]/, ''), v))
               else