Always translate the log level.

Fixes the error "Invalid log level.  Using the default instead." produced when specifying the 'verbose' or 'http' log levels. Also add the 'debug' level mapping.

index.js

@@ -11,6 +11,7 @@ const levelTranslate = new Map([
 , ['info', 'info']
 , ['http', 'debug']
 , ['verbose', 'debug']
+, ['debug', 'debug']
 , ['silly', 'trace']
 ])
 /*
@@ -28,19 +29,21 @@ module.exports = class LogDNATransport extends Transport {
   }
 
   log(info, callback) {
+    const level = levelTranslate.get(info.level)
+
     if (info.error instanceof Error) {
       info.error = info.error.stack || info.error.toString()
     }
 
     if (!info.message) {
       // Send the incoming object payload as the message
-      const level = levelTranslate.get(info.level)
       this.logger.log(info, level)
       callback(null, true)
       return
     }
 
-    const {level, message, indexMeta, timestamp, ...meta} = info
+    // eslint-disable-next-line no-unused-vars
+    const {level: _, message, indexMeta, timestamp, ...meta} = info
     const opts = {
       level
     , indexMeta