Selecting to upgrade a service in the local charm upgrade inspector upgrades the services charm
added tests for the local charm upgrade functionality
Merge pull request #153 from hatched/upgrade-from-local-charm

To QA
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**Use real env (ec2, lxc)**
- Deploy a local charm
- Drag the same local charm to the canvas, an inspector which gives you the option to upload or upgrade should come up
- Upload and deploy another version of the charm (so you now have two services with the same charm)
- Wait for both to come up.
- View the inspector for both services and take note of the charm url. One should be a higher version than the other.
- Drag the same local charm to the canvas and select a single service to upgrade.
- Wait 10s or so
- Click that services inspector and it should have a different charm url now.