fix: upgrade nodejs version to 15.11

Dockerfile-development

-FROM node:12.21
+FROM node:15.11
 RUN apt-get update && apt-get -y install curl vim bash nano
 
 WORKDIR /home/node/app

Dockerfile-production

 # IMAGE FOR BUILDING
-FROM node:12.21-alpine as build
+FROM node:15.11-alpine as build
 
 ARG instance_name
 ARG node_env
@@ -45,7 +45,7 @@ COPY . .
 RUN yarn webpack --config webpack/webpack.production.config.js
 
 # IMAGE FOR RUNNING
-FROM node:12.21-alpine as server
+FROM node:15.11-alpine as server
 
 WORKDIR /home/node/app