allow to config corePluginsPath

Author: NickOvt

config/default.js

@@ -515,5 +515,6 @@ module.exports = {
         */
     },
 
-    pluginsPath: './plugins'
+    pluginsPath: './plugins',
+    corePluginsPath: './plugins'
 };

lib/plugins.js

@@ -11,6 +11,7 @@ module.exports.init = context => {
     module.exports.handler = new PluginHandler({
         logger: log,
         pluginsPath: config.pluginsPath,
+        corePluginsPath: config.pluginsPath,
         plugins: config.plugins,
         context,
         log: config.log,