add: VTK lastest versions

var/spack/repos/builtin/packages/vtk/package.py

@@ -7,6 +7,10 @@ class Vtk(Package):
     homepage = "http://www.vtk.org"
     url      = "http://www.vtk.org/files/release/6.1/VTK-6.1.0.tar.gz"
 
+    version("7.0.0", "5fe35312db5fb2341139b8e4955c367d", url="http://www.vtk.org/files/release/7.0/VTK-7.0.0.tar.gz")
+
+    version("6.3.0", '0231ca4840408e9dd60af48b314c5b6d', url="http://www.vtk.org/files/release/6.3/VTK-6.3.0.tar.gz")
+
     version('6.1.0', '25e4dfb3bad778722dcaec80cd5dab7d')
 
     depends_on("qt")