removed pde nature and builders from the project

examples/traffic_light/.project

@@ -10,16 +10,6 @@
 			<arguments>
 			</arguments>
 		</buildCommand>
-		<buildCommand>
-			<name>org.eclipse.pde.ManifestBuilder</name>
-			<arguments>
-			</arguments>
-		</buildCommand>
-		<buildCommand>
-			<name>org.eclipse.pde.SchemaBuilder</name>
-			<arguments>
-			</arguments>
-		</buildCommand>
 		<buildCommand>
 			<name>org.eclipse.xtext.ui.shared.xtextBuilder</name>
 			<arguments>
@@ -33,7 +23,6 @@
 	</buildSpec>
 	<natures>
 		<nature>org.eclipse.jdt.core.javanature</nature>
-		<nature>org.eclipse.pde.PluginNature</nature>
 		<nature>org.yakindu.sct.builder.SCTNature</nature>
 		<nature>org.eclipse.xtext.ui.shared.xtextNature</nature>
 	</natures>