Add default file header to EDGE-T reporting script.

scripts/output/single/EDGETransportValidation.R

+# |  (C) 2006-2019 Potsdam Institute for Climate Impact Research (PIK)
+# |  authors, and contributors see CITATION.cff file. This file is part
+# |  of REMIND and licensed under AGPL-3.0-or-later. Under Section 7 of
+# |  AGPL-3.0, you are granted additional permissions described in the
+# |  REMIND License Exception, version 1.0 (see LICENSE file).
+# |  Contact: remind@pik-potsdam.de
+
 require(rmarkdown)
 require(lucode)