Fix Credo Readability (strict)

- Max line length, implicit try, alias order, zero-arity defs
- String sigils, long comments split; redundant blank lines fixed

lib/mv/membership/members_csv.ex

@@ -74,11 +74,9 @@ defmodule Mv.Membership.MembersCSV do
   defp key_to_atom(k) when is_atom(k), do: k
 
   defp key_to_atom(k) when is_binary(k) do
-    try do
-      String.to_existing_atom(k)
-    rescue
-      ArgumentError -> k
-    end
+    String.to_existing_atom(k)
+  rescue
+    ArgumentError -> k
   end
 
   defp get_cfv_by_id(member, id) do