added default mongoose connection

services/web/app/coffee/infrastructure/Mongoose.coffee

@@ -0,0 +1,16 @@
+mongoose = require('mongoose')
+Settings = require 'settings-sharelatex'
+logger = require('logger-sharelatex')
+
+mongoose.connect(Settings.mongo.url, server: poolSize: 10)
+
+mongoose.connection.on 'connected', () ->
+	logger.log {url:Settings.mongo.url}, 'mongoose default connection open'
+
+mongoose.connection.on 'error', (err) ->
+	logger.err err:err, 'mongoose error on default connection';
+
+mongoose.connection.on 'disconnected', () ->
+	logger.log 'mongoose default connection disconnected'
+
+module.exports = mongoose