Trouble deploying server-side to Heroku

[jessamarie]

API repo: https://github.com/jessamarie/recall-api

I've created an API to fetch data from. It's all working locally, but I am having trouble properly deploying it. Here are the steps I have taken:

1. Created heroku app and a deploying branch.
2. Created account on MLAB
3. Set an env variable with the database URI like so: MONGOLAB_URI="mongodb://<myactualuser>:<myactualpassword>@ds135624.mlab.com:35624/recall_prod"
4. Updated production database to be equal to process.env.MONGOLAB_URI, as shown here: https://github.com/jessamarie/recall-api/blob/master/config/env/production.js
5. Deployed to heroku with: git push heroku deploying:master

https://recall-app-api.herokuapp.com/api/topics should display an array of objects, but instead I get an error that says: "Application error. An error occurred in the application and your page could not be served. If you are the application owner, check your logs for details."

Build log:

-----> Node.js app detected
-----> Creating runtime environment

       NPM_CONFIG_LOGLEVEL=error
       NPM_CONFIG_PRODUCTION=true
       NODE_VERBOSE=false
       NODE_ENV=production
       NODE_MODULES_CACHE=true
-----> Installing binaries
       engines.node (package.json):  unspecified
       engines.npm (package.json):   unspecified (use default)

       Resolving node version 6.x...
       Downloading and installing node 6.11.3...
       Detected package-lock.json: defaulting npm to version 5.x.x
       Bootstrapping npm 5.x.x (replacing 3.10.10)...
       npm 5.4.2 installed
-----> Restoring cache
       Loading 2 from cacheDirectories (default):
       - node_modules
       - bower_components (not cached - skipping)
-----> Building dependencies
       Installing node modules (package.json + package-lock)
       up to date in 1.283s
-----> Caching build
       Clearing previous node cache
       Saving 2 cacheDirectories (default):
       - node_modules
       - bower_components (nothing to cache)
-----> Build succeeded!
-----> Discovering process types
       Procfile declares types     -> (none)
       Default types for buildpack -> web
-----> Compressing...
       Done: 17.6M
-----> Launching...
       Released v4
       https://recall-app-api.herokuapp.com/ deployed to Heroku

[AndyWhitley]

@jessamarie Have you run your seed file yet?

[jessamarie]

@AWhitleyGA When I do that I get this error in the terminal:

[jessa@Jessicas-MacBook-Pro recall-api]$  heroku run npm run seed
 ▸    heroku-cli: update available from 6.13.10 to 6.14.21-d83c94b
Running npm run seed on ⬢ recall-app-api... up, run.3062 (Free)

> recall-api@1.0.0 seed /app
> node config/db/seed.js

(node:18) DeprecationWarning: `open()` is deprecated in mongoose >= 4.11.0, use `openUri()` instead, or set the `useMongoClient` option if using `connect()` or `createConnection()`. See http://mongoosejs.com/docs/connections.html#use-mongo-client
(node:18) DeprecationWarning: Mongoose: mpromise (mongoose's default promise library) is deprecated, plug in your own promise library instead: http://mongoosejs.com/docs/promises.html
{ MongoError: failed to connect to server [undefined:27017] on first connect [MongoError: getaddrinfo ENOTFOUND undefined undefined:27017]
    at Pool.<anonymous> (/app/node_modules/mongodb-core/lib/topologies/server.js:336:35)
    at emitOne (events.js:96:13)
    at Pool.emit (events.js:188:7)
    at Connection.<anonymous> (/app/node_modules/mongodb-core/lib/connection/pool.js:280:12)
    at Connection.g (events.js:292:16)
    at emitTwo (events.js:106:13)
    at Connection.emit (events.js:191:7)
    at Socket.<anonymous> (/app/node_modules/mongodb-core/lib/connection/connection.js:187:49)
    at Socket.g (events.js:292:16)
    at emitOne (events.js:96:13)
    at Socket.emit (events.js:188:7)
    at connectErrorNT (net.js:1021:8)
    at _combinedTickCallback (internal/process/next_tick.js:80:11)
    at process._tickCallback (internal/process/next_tick.js:104:9)
  name: 'MongoError',
  message: 'failed to connect to server [undefined:27017] on first connect [MongoError: getaddrinfo ENOTFOUND undefined undefined:27017]' }

[AndyWhitley]

@jessamarie What file is this require statement supposed to be pointing at? https://github.com/jessamarie/recall-api/blob/master/config/db/connect.js#L4