How to apt-get install in a GitHub action? : <p>In the new GitHub actions, I am trying to install a package in order to use it in one of the next steps.</p>

<pre><code>name: CI

on: [push, pull_request]

jobs:
  translations:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v1
      with:
        fetch-depth: 1
    - name: Install xmllint
      run: apt-get install libxml2-utils
    # ...
</code></pre>

<p>However this fails with</p>

<pre><code>Run apt-get install libxml2-utils
  apt-get install libxml2-utils
  shell: /bin/bash -e {0}
E: Could not open lock file /var/lib/dpkg/lock-frontend - open (13: Permission denied)
E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), are you root?
##[error]Process completed with exit code 100.
</code></pre>

<p>What's the best way to do this? Do it need to reach for Docker?</p>
