LMA plugins use tox to run their tests

The LMA plugins (collector [1], Elasticsearch-Kibana[2], InfluxDB-Grafana [3] and infrastructure alerting [4]) have added a tox.ini file that runs all the necessary tests:
- Puppet lint
- Puppet metadata lint
- Puppet syntax checker
- Puppet rspec tests
More tests will be added in the future like PEP8 and unit tests for Python modules.

We'd like to update the Jenkins jobs associated to the LMA plugins to run tox instead of the custom script actually configured (which doesn't run the Puppet rspec tests for instance).

[1] https://github.com/stackforge/fuel-plugin-lma-collector
[2] https://github.com/stackforge/fuel-plugin-elasticsearch-kibana
[3] https://github.com/stackforge/fuel-plugin-influxdb-grafana
[4] https://github.com/stackforge/fuel-plugin-lma-infrastructure-alerting