I have deployed my code in Heroku but every time I am facing same error about nodemailer version

I am using 0.7.1 version of node mailer only This is the error I am getting in Heroku logs

2017-06-02T07:23:40.094156+00:00 app[web.1]: at Nodemailer.sendMail (/app/node_modules/nodemailer/lib/nodemailer.js:274:18) 2017-06-02T07:23:40.094128+00:00 app[web.1]: err Error: Unsupported configuration, downgrade Nodemailer to v0.7.1 to use it 2017-06-02T07:23:40.094157+00:00 app[web.1]: at /app/authenticate-service.js:123:28 2017-06-02T07:23:40.094158+00:00 app[web.1]: at Query. (/app/node_modules/mongoose/lib/model.js:3336:16) 2017-06-02T07:23:40.094159+00:00 app[web.1]: at /app/node_modules/kareem/index.js:127:16 2017-06-02T07:23:40.094158+00:00 app[web.1]: at /app/node_modules/kareem/index.js:259:21 2017-06-02T07:23:40.094160+00:00 app[web.1]: at _combinedTickCallback (internal/process/next_tick.js:73:7) 2017-06-02T07:23:40.094160+00:00 app[web.1]: at process._tickCallback (internal/process/next_tick.js:104:9)

via Ikshit Mathur