title: Update SQLite in travis CI
body: <p>On python 3.6 and 3.7 (django 2.2) I am getting 
  <code>django.core.exceptions.ImproperlyConfigured: SQLite 3.8.3 or later is required (found 3.8.2).</code>
  On TravisCI</p>
  
  <h3>What I Did</h3>
  
  <ul>
  <li>I tried installing it with addons:</li>
  </ul>
  
  <pre><code>addons:
    apt:
      sources:
        - travis-ci/sqlite3
      packages:
        - sqlite3
  </code></pre>
  
  <p>The sources here got ignored</p>
  
  <pre><code>Disallowing sources: travis-ci/sqlite3
  To add unlisted APT sources, follow instructions in https://docs.travis-ci.com/user/installing-dependencies#Installing-Packages-with-the-APT-Addon
  </code></pre>
  
  <ul>
  <li>And with ppa in before_install</li>
  </ul>
  
  <pre><code>before_install:
    - sudo apt-add-repository -y ppa:travis-ci/sqlite3
    - sudo apt-get -y update
    - sudo apt-get -y install sqlite3=3.7.15.1-1~travis1
  </code></pre>
  
  <p>error:</p>
  
  <pre><code>Cannot add PPA: 'ppa:travis-ci/sqlite3'.
  Please check that the PPA name or format is correct.
  </code></pre>
  
  <p>How can I get it to work?</p>
  
  <p>Sources
  <a href="https://github.com/travis-ci/apt-package-safelist/issues/368#issuecomment-198586476" rel="noreferrer">https://github.com/travis-ci/apt-package-safelist/issues/368#issuecomment-198586476</a></p>