Code review comment for ~vlgrevtsev/ntp-charm:lp1835766

> There's nothing to install the 'ntpdate' package, from universe.

I've tested this on an LXC on trusty:

$ apt-cache policy ntpdate
ntpdate:
  Installed: 1:4.2.6.p5+dfsg-3ubuntu2.14.04.13
  Candidate: 1:4.2.6.p5+dfsg-3ubuntu2.14.04.13
  Version table:
 *** 1:4.2.6.p5+dfsg-3ubuntu2.14.04.13 0
        500 http://archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu/ trusty-security/main amd64 Packages
        100 /var/lib/dpkg/status
     1:4.2.6.p5+dfsg-3ubuntu2 0
        500 http://archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages

And on an LXC on xenial:

$ apt-cache policy ntpdate
ntpdate:
  Installed: (none)
  Candidate: 1:4.2.8p4+dfsg-3ubuntu5.9
  Version table:
     1:4.2.8p4+dfsg-3ubuntu5.9 500
        500 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu xenial-security/main amd64 Packages
     1:4.2.8p4+dfsg-3ubuntu5 500
        500 http://archive.ubuntu.com/ubuntu xenial/main amd64 Packages

And on LXC in bionic:

$ apt-cache policy ntpdate
ntpdate:
  Installed: (none)
  Candidate: 1:4.2.8p10+dfsg-5ubuntu7.1
  Version table:
     1:4.2.8p10+dfsg-5ubuntu7.1 500
        500 http://archive.ubuntu.com/ubuntu bionic-updates/universe amd64 Packages
        500 http://security.ubuntu.com/ubuntu bionic-security/universe amd64 Packages
     1:4.2.8p10+dfsg-5ubuntu7 500
        500 http://archive.ubuntu.com/ubuntu bionic/universe amd64 Packages

So it seems like configuring universe would be needed if we're on bionic, just to clarify.