add license text to all CSPP Geo GGLM code

gridded_glm/bin/cspp-geo-gglm-make-grids.sh

 #!/usr/bin/env bash
 # encoding: utf-8
-# Copyright (C) 2019 Space Science and Engineering Center (SSEC),
+# Copyright (C) 2019-2021 Space Science and Engineering Center (SSEC),
 #  University of Wisconsin-Madison.
 #
 #     This program is free software: you can redistribute it and/or modify

gridded_glm/bin/cspp-geo-gglm.sh

 #!/usr/bin/env bash
 # encoding: utf-8
-# Copyright (C) 2019 Space Science and Engineering Center (SSEC),
+# Copyright (C) 2019-2021 Space Science and Engineering Center (SSEC),
 #  University of Wisconsin-Madison.
 #
 #     This program is free software: you can redistribute it and/or modify

gridded_glm/libexec/_minute_gridder.py

 #!/usr/bin/env python3
-# Based on https://github.com/deeplycloudy/glmtools/blob/master/examples/grid/make_GLM_grids.py
+"""
+Copyright (C) 2020-2021 Space Science and Engineering Center (SSEC), University of Wisconsin-Madison.
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+This file is part of the CSPP Geo Gridded GLM software package. CSPP Geo
+Gridded GLM takes GOES GLM Level 2 LCFA files and grids them to the ABI
+fixed grid. It does this using the open source glmtools python package by
+Eric Bruning. glmtools can be found in the runtime directory of this package
+or at https://github.com/deeplycloudy/glmtools.
+"""
 
 parse_desc = """Create one minute NetCDF4 grids (and, optionally, AWIPS-compatible tiles) from GLM flash data.