Fix typo: cache_enabled -> template_cache_enabled

Author: AZQ1994

lib/simple_json.rb

@@ -11,7 +11,7 @@
 
 module SimpleJson
   @config = {
-    cache_enabled: false,
+    template_cache_enabled: false,
     template_paths: ['app/views'],
     cache_key_prefix: 'simple_json/views',
     default_json_module: ActiveSupport::JSON