Use dynamic properties for onetemplate mapping

* Refactor login + invocation into separate module
* Assign properties dynamically
* Test for correct invocation & stub out executables
Extract ERB templates from puppet providers

* Pull out ERBs into a separate module and just include them from there
Fixed invocation to + test with real markup

* Use current instance instead of classes
* Add a proper XML file for testing
* Clarify variable names
* Extract invocation into single class
Merge pull request #1 from bascht/feature/dynamic-properties

Dynamic properties & reusable command line implementation