Update copyright year to 2018

debian/copyright

@@ -3,7 +3,7 @@ Upstream-Name: writeas-gtk
 Source: https://code.as/writeas/writeas-gtk/
 
 Files: *
-Copyright: 2017 A Bunch Tell LLC <hello@write.as>
+Copyright: 2018 A Bunch Tell LLC <hello@write.as>
 License: GPL-3.0+
 
 License: GPL-3.0+