fix(variable): move to const where possible

Author: sonicoder86

README.md

@@ -9,8 +9,8 @@ It has the same logging levels as [bunyan].
 
 ```javascript
 process.env.DEBUG = 'redis';
-let mongoLogger = require('@emartech/json-logger')('mongo');
-let redisLogger = require('@emartech/json-logger')('redis');
+const mongoLogger = require('@emartech/json-logger')('mongo');
+const redisLogger = require('@emartech/json-logger')('redis');
 
 // simple info logging with enabled namespace
 redisLogger.info('connected', { domain: 'yahoo' });

example.js

@@ -1,9 +1,10 @@
 'use strict';
+
 process.env.DEBUG = 'redis';
-let logger = require('./index');
+const logger = require('./index');
 
-let mongoLogger = logger('mongo');
-let redisLogger = logger('redis');
+const mongoLogger = logger('mongo');
+const redisLogger = logger('redis');
 
 // simple info logging with enabled namespace
 redisLogger.info('connected', { domain: 'yahoo' });

src/logger/logger.js

@@ -4,7 +4,7 @@ const config = require('../config');
 const continuationLocalStorage = require('cls-hooked');
 const STACK_TRACE_LIMIT = 4000;
 
-let logMethodFactory = function(level) {
+const logMethodFactory = function(level) {
   return function(action, data) {
     if (!this.enabled) {
       return;

src/output/color-name/color-name.js

@@ -12,7 +12,7 @@ module.exports = function colorName(name) {
     colorCounter++;
   }
 
-  let color = colors[names[name].color];
+  const color = colors[names[name].color];
   return chalk[color](name);
 };
 

src/output/format-body/format-body.js

@@ -14,7 +14,7 @@ module.exports = function(logBody) {
     delete log.msg;
   }
 
-  let keys = Object.keys(log);
+  const keys = Object.keys(log);
 
   return keys
     .sort()