Juju 1.17.1 broken on MAAS - solution

[Ian Booth]

Hi folks

To cut a long story short, the recent Juju 1.17.1 release can't find tools when
bootstrapping a MAAS environment using --upload-tools. There will be a fix
pushed to trunk tomorrow, but in the interim, to make 1.17.1 work, add this
config setting to your MAAS environ config in your environments.yaml file:

tools-metadata-url = http://juju-dist.s3.amazonaws.com/tools