migrate from underscore to lodash

app/js/DockerRunner.js

@@ -25,7 +25,7 @@ const async = require('async')
 const LockManager = require('./DockerLockManager')
 const fs = require('fs')
 const Path = require('path')
-const _ = require('underscore')
+const _ = require('lodash')
 const metrics = require('metrics-sharelatex')
 
 logger.info('using docker runner')

app/js/OutputCacheManager.js

@@ -19,7 +19,7 @@ const fs = require('fs')
 const fse = require('fs-extra')
 const Path = require('path')
 const logger = require('logger-sharelatex')
-const _ = require('underscore')
+const _ = require('lodash')
 const Settings = require('settings-sharelatex')
 const crypto = require('crypto')
 

app/js/OutputFileOptimiser.js

@@ -19,7 +19,7 @@ const Path = require('path')
 const { spawn } = require('child_process')
 const logger = require('logger-sharelatex')
 const Metrics = require('./Metrics')
-const _ = require('underscore')
+const _ = require('lodash')
 
 module.exports = OutputFileOptimiser = {
   optimiseFile(src, dst, callback) {

app/js/db.js

@@ -10,7 +10,7 @@
  */
 const Sequelize = require('sequelize')
 const Settings = require('settings-sharelatex')
-const _ = require('underscore')
+const _ = require('lodash')
 const logger = require('logger-sharelatex')
 
 const options = _.extend({ logging: false }, Settings.mysql.clsi)