travis: Enable debug logging for juju bootstrap

The functional tests are consistently timing out atm in the juju
bootstrap stage.  Enable debug log so we can se what is going on.

.travis.yml

@@ -18,9 +18,10 @@ script:
        sudo snap install juju --classic;
        sudo sh -c 'echo PATH=/snap/bin:$PATH >> /etc/environment';
        sudo lxd waitready;
+       sudo journalctl --no-pager -xe;
        sudo lxd init --auto;
        sudo usermod -a -G lxd travis;
-       sudo su travis -c 'juju bootstrap --no-gui localhost';
+       sudo su travis -c 'juju bootstrap --debug --no-gui localhost';
     fi
   - tox -c tox.ini -e $ENV
   - if [ $ENV = 'func-travis' ]; then