lib/models/revision.js: make independent of exec-path

Previously calling `app.js` from another directory than
the base directory of CodiMD would result in an error being
thrown because `lib/workers/dmpWorker.js` could not be found.

This change makes the function call independent of the path CodiMD
is started from.

Signed-off-by: WilliButz <wbutz@cyberfnord.de>

Author: WilliButz

lib/models/revision.js

@@ -5,6 +5,7 @@ var async = require('async')
 var moment = require('moment')
 var childProcess = require('child_process')
 var shortId = require('shortid')
+var path = require('path')
 
 // core
 var config = require('../config')
@@ -14,7 +15,7 @@ var dmpWorker = createDmpWorker()
 var dmpCallbackCache = {}
 
 function createDmpWorker () {
-  var worker = childProcess.fork('./lib/workers/dmpWorker.js', {
+  var worker = childProcess.fork(path.resolve(__dirname, '../workers/dmpWorker.js'), {
     stdio: 'ignore'
   })
   if (config.debug) logger.info('dmp worker process started')