configurable port for app and development

application port: PORT
port for development: PORT_DEV
PORT_DEV will take effect when run gulp browser-sync.
Meaning that PORT_DEV will take effect when run `npm run dev` too.

.env.template

@@ -2,6 +2,8 @@
   "SESSION_SECRET": "DEFAULT",
   "LOGGER_SILENT": "false",
   "LOGGER_LEVEL": "info",
+  "PORT": 5000,
+  "PORT_DEV": 3000,
 
   "KANCOLLE_SERVER_MASTER": "http://203.104.209.7",
   "KANCOLLE_SERVER_1"     : "http://203.104.209.71",

gulpfile.js

@@ -1,5 +1,10 @@
 'use strict'
 
+const appPort = process.env.PORT
+const devPort = process.env.PORT_DEV
+const css = 'src/views/*.css'
+const htmlTemplate = 'src/views/**/*.hbs'
+
 const gulp = require('gulp')
 const postcss = require('gulp-postcss')
 const autoprefixer = require('autoprefixer')
@@ -8,10 +13,6 @@ const rename = require('gulp-rename')
 const bs = require('browser-sync').create()
 const nodemon = require('gulp-nodemon')
 
-const devPort = 8080
-const css = 'src/views/*.css'
-const htmlTemplate = 'src/views/**/*.hbs'
-
 gulp.task('build', ['build:css'])
 
 gulp.task('build:css', () => {
@@ -28,7 +29,7 @@ gulp.task('nodemon', done => {
   return nodemon({
     script: 'bin/www',
     ignore: ['gulpfile.js', 'node_modules/', 'src/views/'],
-    env: {PORT: devPort}
+    env: {PORT: appPort}
   })
   .on('start', () => {
     if(!start) {
@@ -40,7 +41,8 @@ gulp.task('nodemon', done => {
 
 gulp.task('browser-sync', ['nodemon'], () => {
   bs.init({
-    proxy: `localhost:${devPort}`,
+    proxy: `localhost:${appPort}`,
+    port: devPort,
     open: false
   })