mix.exs: Make copyright regexes more precise

- Add copyright checks for Pleroma's not any copyright
- Copyright bump fixes the whole line instead of just the year

mix.exs

@@ -345,18 +345,19 @@ defmodule Pleroma.Mixfile do
 ] |> String.replace("\n", "\\n")
 
     find = "find lib test priv -type f \\( -name '*.ex' -or -name '*.exs' \\) -exec "
-    grep = "grep -L '# Copyright' {} \\; |"
+    grep = "grep -L '# Copyright © [0-9\-]* Pleroma' {} \\;"
     xargs = "xargs -n1 sed -i'' '1s;^;#{template};'"
 
-    :os.cmd(String.to_charlist("#{find}#{grep}#{xargs}"))
+    :os.cmd(String.to_charlist("#{find}#{grep} | #{xargs}"))
   end
 
   defp bump_copyright(_) do
     year = NaiveDateTime.utc_now().year
-    find = "find lib test priv -type f \\( -name '*.ex' -or -name '*.exs' \\) |"
+    find = "find lib test priv -type f \\( -name '*.ex' -or -name '*.exs' \\)"
 
-    xargs = "xargs sed -i'' 's/# Copyright © 2017-20[0-9][0-9]/# Copyright © 2017-#{year}/'"
+    xargs =
+      "xargs sed -i'' 's;# Copyright © [0-9\-]* Pleroma.*$;# Copyright © 2017-#{year} Pleroma Authors <https://pleroma.social/>;'"
 
-    :os.cmd(String.to_charlist("#{find}#{xargs}"))
+    :os.cmd(String.to_charlist("#{find} | #{xargs}"))
   end
 end