build: update copyright years to 2019

cli/mmcli.c

@@ -138,7 +138,7 @@ print_version_and_exit (void)
 {
     g_print ("\n"
              PROGRAM_NAME " " PROGRAM_VERSION "\n"
-             "Copyright (2011 - 2016) Aleksander Morgado\n"
+             "Copyright (2011 - 2019) Aleksander Morgado\n"
              "License GPLv2+: GNU GPL version 2 or later <http://gnu.org/licenses/gpl-2.0.html>\n"
              "This is free software: you are free to change and redistribute it.\n"
              "There is NO WARRANTY, to the extent permitted by law.\n"

docs/reference/api/ModemManager-docs.xml

@@ -50,6 +50,7 @@
       <year>2016</year>
       <year>2017</year>
       <year>2018</year>
+      <year>2019</year>
       <holder>The ModemManager Authors</holder>
     </copyright>
 

docs/reference/libmm-glib/libmm-glib-docs.xml

@@ -38,6 +38,7 @@
       <year>2016</year>
       <year>2017</year>
       <year>2018</year>
+      <year>2019</year>
       <holder>The ModemManager Authors</holder>
     </copyright>
 

src/mm-context.c

@@ -281,7 +281,7 @@ print_version (void)
 {
     g_print ("\n"
              "ModemManager " MM_DIST_VERSION "\n"
-             "Copyright (C) 2008-2017 The ModemManager authors\n"
+             "Copyright (C) 2008-2019 The ModemManager authors\n"
              "License GPLv2+: GNU GPL version 2 or later <http://gnu.org/licenses/gpl-2.0.html>\n"
              "This is free software: you are free to change and redistribute it.\n"
              "There is NO WARRANTY, to the extent permitted by law.\n"