Ensure that tests pass on every user setup.

A local gerrit must be run, and a sonar user with ssh access set up.
Requirements are documented at README.md

Change-Id: If1a3c0dde14a7b5251bdf800b95229cefbe1c403
Merge branch 'master' of github.com:sgala/gerrit-intergation-plugin
Add more configurations

Let sonar admin configure which vote to cast in case of
no alerts, warning, or errors; also permits to select
a subset of metrics that are evaluated for the vote.

Updating sonar-api to 3.3 for PropertyType.METRIC
Get rid of static GerritCommand, need settings from Notifier
Add analysis result message in gerrit core-review
Fix tests

Make tests compile again, delete one test (not relevant anymore) and
ignore a couple that still needs refactoring.
Merge pull request #2 from guidograzioli/master

Add sonar vote configuration