Merge pull request #2 from ionutbalutoiu/master

Updated README and added hooks
Upgraded README and charm metadata:

* Added caveats section to README.md
* Added default values to config.yaml
* Added default values to metadata.yaml
Merge pull request #3 from perrito666/master

Upgraded README and charm metadata:
refactored paths and casing to meet juju guidelines
Changed pester download location to temp folder
Execution policy should be bypass to execute tests
Fixed get-requirements temp path