Heroku compatible

[uetchy]

Hi, I did some fix to add Heroku compatibility support.
We'll can push lgtm service on Heroku and/or similar PaaS.
I've tested this on Heroku and it seems to work quite well.

How to put lgtmco/lgtm to Heroku

# move to lgtm repo
cd $GOPATH/github.com/lgtmco/lgtm

# create Heroku app
heroku create

# add database plugin (e.g. JawsDB for MySQL)
heroku addons:create jawsdb:kitefin

# upload config vars to Heroku as you like
heroku config:set DATABASE_DRIVER=mysql
heroku config:set DATABASE_DATASOURCE='user:pass@tcp(hostname:3306)/databasename?parseTime=true'
heroku config:set GITHUB_CLIENT=<github client token>
heroku config:set GITHUB_SECRET=<github secret token>
heroku config:set GITHUB_SCOPE='user:email,read:org,repo'
heroku config:set GITHUB_URL='https://github.com'

# build Docker image and push to Heroku Container Registry
heroku container:push web

# open browser
heroku open

[uetchy]

What do you think? @bradrydzewski

[rzane]

Thanks for this, @uetchy. Your instructions worked like a charm!