add pnml ecore files and initial test

...test/java/de/tudresden/inf/st/e2j/TransformationTest.java

src/test/resources/ecore/pnml/LICENSE.md

src/test/resources/ecore/pnml/arbitrarydeclarations.ecore

src/test/resources/ecore/pnml/booleans.ecore

src/test/resources/ecore/pnml/cyclicEnumerations.ecore

src/test/resources/ecore/pnml/dots.ecore

src/test/resources/ecore/pnml/finiteEnumerations.ecore

src/test/resources/ecore/pnml/finiteIntRanges.ecore

src/test/resources/ecore/pnml/hlcorestructure.ecore

src/test/resources/ecore/pnml/integers.ecore

src/test/resources/ecore/pnml/lists.ecore

src/test/resources/ecore/pnml/multisets.ecore

src/test/resources/ecore/pnml/partitions.ecore

src/test/resources/ecore/pnml/placeTransition.ecore

src/test/resources/ecore/pnml/pnmlcoremodel.ecore

src/test/resources/ecore/pnml/strings.ecore

src/test/resources/ecore/pnml/terms.ecore