xbase dependencies are not required anymore

plugins/org.yakindu.sct.model.sgen/META-INF/MANIFEST.MF

@@ -14,7 +14,5 @@ Require-Bundle: org.eclipse.core.runtime,
  org.eclipse.emf.ecore;visibility:=reexport,
  org.yakindu.sct.model.sgraph;visibility:=reexport,
  org.eclipse.emf.ecore.xmi;bundle-version="2.7.0",
- org.eclipse.xtext.xbase;bundle-version="2.0.0";visibility:=reexport,
- com.google.inject;bundle-version="2.0.0";visibility:=reexport,
- org.eclipse.xtext.purexbase;bundle-version="2.0.0"
+ com.google.inject;bundle-version="2.0.0";visibility:=reexport
 Bundle-ActivationPolicy: lazy