Merge pull request circleci#1954 from circleci/add-db-to-test-page

add the database config link to the test landing page

Author: michelle-luna

jekyll/_cci2/test.md

@@ -15,6 +15,7 @@ Document | Description
 <a href="{{ site.baseurl }}/2.0/testing-ios/">Testing iOS Applications on macOS</a> | How to set up and customize testing for an iOS application with CircleCI.
 <a href="{{ site.baseurl }}/2.0/parallelism-faster-jobs/">Running Tests in Parallel</a> | How to glob and splitting tests inside a job.
 <a href="{{ site.baseurl }}/2.0/project-walkthrough/#install-and-run-selenium-to-automate-browser-testing">Install and Run Selenium to Automate Browser Testing</a> | Automate your browser tests. 
+<a href="{{ site.baseurl }}/2.0/postgres-config/">Configuring Databases</a> | Configuring a database container using Postgres and Rails. 
 **Code Signing** |
 <a href="{{ site.baseurl }}/2.0/ios-codesigning/">Setting Up Code Signing for iOS Projects</a> | Describes the guidelines for setting up code signing for your iOS or Mac project on CircleCI 2.0.
 {: class="table table-striped"}