set newer docker image for Meteor 1.6.1 and ignore local mup files

Author: lmachens

.gitignore

@@ -1,3 +1,5 @@
 node_modules
 custom.bootstrap.less
-custom.bootstrap.mixins.import.less
+custom.bootstrap.mixins.import.less
+mup.js
+settings.json

mup-placeholder.js

@@ -23,7 +23,7 @@ module.exports = {
       MONGO_OPLOG_URL: 'mongodb://mongodb/local'
     },
     docker: {
-      image: 'abernix/meteord:node-8.4.0-base',
+      image: 'abernix/meteord:node-8.9.3-base',
       args: [
         '-p 11011:11011', // Open up the engine port
         '--log-driver json-file', // Without these the Docker log file for Mongo will exhaust disk space

settings-placeholder.json

@@ -0,0 +1,3 @@
+{
+  "metricsLifetime": 604800000
+}