title: Puppet can't downgrade with ensure installed/latest
body: <p>I'm using the following in my Puppet manifest:</p>
  
  <pre><code>$packages = [
    '2klic-gateway=2.10.5',
  ]
  
  package { $packages: ensure =&gt; latest }
  </code></pre>
  
  <p>Also tried using <code>installed</code> instead of <code>latest</code>. But I get back the following error:</p>
  
  <pre><code>Error: Could not update: Execution of '/usr/bin/apt-get q -y -o DPkg::Options::=-force-confold install 2klic-gateway=2.10.5' returned 100: Reading package lists...
  Building dependency tree...
  Reading state information...
  The following package was automatically installed and is no longer required:
  2klic-updates
  Use 'apt-get autoremove' to remove it.
  The following packages will be DOWNGRADED:
  2klic-gateway
  0 upgraded, 0 newly installed, 1 downgraded, 0 to remove and 5 not upgraded.
  Need to get 22.0 MB of archives.
  After this operation, 312 kB disk space will be freed.
  E: There are problems and -y was used without --force-yes
  Error: /Stage[main]/Main/Node[default]/Package[2klic-gateway=2.10.5]/ensure: change from purged to latest failed: Could not update: Execution of '/usr/bin/apt-get q -y -o DPkg::Options::=-force-confold install 2klic-gateway=2.10.5' returned 100: Reading package lists...
  Building dependency tree...
  Reading state information...
  The following package was automatically installed and is no longer required:
  2klic-updates
  Use 'apt-get autoremove' to remove it.
  The following packages will be DOWNGRADED:
  2klic-gateway
  0 upgraded, 0 newly installed, 1 downgraded, 0 to remove and 5 not upgraded.
  Need to get 22.0 MB of archives.
  After this operation, 312 kB disk space will be freed.
  E: There are problems and -y was used without --force-yes
  </code></pre>
  
  <p>If I manually ssh into the node I can use <code>apt-get install 2klic-gateway=2.10.5</code> and it works. I can also remove the program and then run puppet and the manifest works fine. But as soon as I add the <code>-y</code> flag I get:</p>
  
  <pre><code>E: There are problems and -y was used without --force-yes
  </code></pre>