create extension

src/freedombone-app-pleroma

     run_system_query_postgresql "ALTER USER pleroma SUPERUSER;"
     run_system_query_postgresql "GRANT ALL ON ALL tables IN SCHEMA public TO pleroma;"
     run_system_query_postgresql "GRANT ALL ON ALL sequences IN SCHEMA public TO pleroma;"
+    run_system_query_postgresql "CREATE EXTENSION citext;"
 
     pleroma_secret=config/dev.secret.exs
     cp config/dev.exs $pleroma_secret
     dpkg -i $erlang_package
     apt-get -yq update
     apt-get -yq install esl-erlang
-    apt-get -yq install elixir
+    apt-get -yq install elixir erlang-xmerl
 
     if [ ! -f /usr/local/bin/mix ]; then
         echo $'/usr/local/bin/mix not found after elixir installation'