Stub out noisy/slow logger-sharelatex and mongojs modules in tests

services/track-changes/app/coffee/MongoManager.coffee

@@ -1,7 +1,6 @@
 {db, ObjectId} = require "./mongojs"
 PackManager = require "./PackManager"
 async = require "async"
-logger = require "logger-sharelatex"
 
 module.exports = MongoManager =
 	getLastCompressedUpdate: (doc_id, callback = (error, update) ->) ->

services/track-changes/test/unit/coffee/MongoManager/MongoManagerTests.coffee

@@ -15,6 +15,8 @@ describe "MongoManager", ->
 			"./mongojs" : { db: @db = {}, ObjectId: ObjectId }
 			"./PackManager" : SandboxedModule.require packModulePath, requires:
 				"./LockManager" : {}
+				"./mongojs": {db: bson: BSON = sinon.stub(), ObjectId}
+				"logger-sharelatex": {}
 		@callback = sinon.stub()
 		@doc_id = ObjectId().toString()
 		@project_id = ObjectId().toString()