Dev setup instructions refer to init_mongo.js which no longer exists

[mmccool]

The setup instructions at https://docs.edgexfoundry.org/Ch-GettingStartedGoDevelopers.html say to do the following to set up MongoDB under Linux for developers:

wget https://github.com/edgexfoundry/docker-edgex-mongo/raw/master/init_mongo.js
sudo -u mongodb mongo < init_mongo.js

Unfortunately, init_mongo.js no longer seems to exist. Either it should be replaced or the instructions should be updated.

[lenny-goodell]

@jpwhitemn , this issue should be closed since no longer supporting Mongo.