Update docker config

[DeeDeeG]

Context

• Fixes some issues that were coming up in Travis CI testing/local testing.
• Adjusted configuration files to be more up-to-date and reliable.

Summary of Changes

• Use the PhantomJS binary posted by Medium at their GitHub repo for a PhantomJS related project, so as to download from the GitHub CDN rather than the BitBucket CDN. GitHub's CDN is more reliable. The PhantomJS download had been failing some of the time when downloading from BitBucket.
  • Yes, that Medium. This is a kind of odd workaround, I guess but it is what it is. Their binary is identical to the one posted at BitBucket; The shasums match and everything.
  • Sha1sum output: f8afc8a24eec34c2badccc93812879a3d6f2caf3 phantomjs-2.1.1-linux-x86_64.tar.bz2
• Add a password to our PostgreSQL database (only within the Docker configuration, so only for development and testing scenarios.)
  • Required as of a month or so ago. See the relevant commit message for details.
  • This is probably the best explanation on a single page about the issue: https://discuss.circleci.com/t/postgresql-image-password-not-specified-issue/34555

Checklist

• [ ] Tested Mobile Responsiveness
• [ ] Added Unit Tests
• [x] CI Passes
• [ ] Deploys to Heroku on test Correctly (Maintainers will handle)
• [ ] Added Documentation (Service and Code when required)

Screenshots

Before

After