Comment 4 for bug 1564622

We can always run `juju-1 version` to find the local version of the binary.

I wonder if we want to give more of an introduction to Juju 2. Something along the lines of:

Welcome to Juju 2.0. The 'juju' command now refers to the 2.0 version of Juju. If you wish to interact with a Juju 1.x environment, please use the existing Juju <1.x.x> command juju-1, as the Juju 2.0 command cannot interact with Juju 1.x environments.

Note that many commands have changed in Juju 2.0. Please see https://jujucharms.com/SomeValidURL for more information, or type 'juju help'.

Would you like to run the 'juju <whatever>' command you entered with juju 2.0? Y/n?