fix: linting issues

Should fix compatibility with Node 5.10.

lib/messages/create.js

@@ -2,7 +2,7 @@ var SMB2Message = require('../tools/smb2-message');
 var message = require('../tools/message');
 var constants = require('../structures/constants');
 
-const desiredAccess =
+var desiredAccess =
   constants.DELETE |
   constants.FILE_APPEND_DATA |
   constants.FILE_DELETE_CHILD |

lib/messages/create_folder.js

@@ -2,7 +2,7 @@ var SMB2Message = require('../tools/smb2-message');
 var message = require('../tools/message');
 var constants = require('../structures/constants');
 
-const desiredAccess =
+var desiredAccess =
   constants.DELETE |
   constants.FILE_APPEND_DATA |
   constants.FILE_DELETE_CHILD |

lib/messages/open_folder.js

@@ -2,7 +2,7 @@ var SMB2Message = require('../tools/smb2-message');
 var message = require('../tools/message');
 var constants = require('../structures/constants');
 
-const desiredAccess =
+var desiredAccess =
   constants.DELETE |
   constants.FILE_APPEND_DATA |
   constants.FILE_DELETE_CHILD |

lib/tools/parse-flags.js

 var c = require('../structures/constants');
 
 module.exports = function parseFlags(flags) {
-  const chars = { __proto__: null };
-  for (let i = 0, n = flags.length; i < n; ++i) {
+  var chars = { __proto__: null };
+  for (var i = 0, n = flags.length; i < n; ++i) {
     chars[flags[i]] = true;
   }
 

test/index.js

+'use strict';
+
 const asyncFn = require('promise-toolbox/asyncFn');
 const defer = require('golike-defer').default;
 const finished = require('readable-stream').finished;