Code review comment for lp:~frankban/charms/trusty/juju-gui/config-version

*** Submitted:

Add the Juju version to the GUI config file.

The version can be specified using a charm option.
If not specified, the Juju version is retrieved
dynamically by calling jujud --version.

Initial implementation by Huw.

Tests: `make unittest`.

QA:
- bootstrap an environment;
- run `make deploy`;
- wait for the unit to be ready;
- run `juju ssh juju-gui/0 cat
/var/lib/juju-gui/juju-gui/build-prod/juju-ui/assets/config.js`
   and check the Juju version is included in the config file;
- run `juju set juju-gui juju-core-version=42.47`;
- check the version is changed to the one specified;
- run `juju unset juju-gui juju-core-version`;
- check the correct version is back in the config file;
- destroy the environment.

Done, thank you!

R=rharding
CC=
https://codereview.appspot.com/188890043

https://codereview.appspot.com/188890043/