use member settings, remove show, tighter pundit

app/policies/member_policy.rb

@@ -1,4 +1,13 @@
-class MemberPolicy < EditOwnPolicy
+class MemberPolicy < AdminPolicy
+
+  def update?
+    return true if member.admin?
+    owner?
+  end
+
+  def owner?
+    member == record.member
+  end
 
   class Scope < Scope
   end