if you uninstall everything these incantations should work.
#####################################################
# install elixir (only need to do once)
#
# UBUNTU:
#
wget https://packages.erlang-solutions.com/erlang-solutions_1.0_all.deb
sudo dpkg -i erlang-solutions_1.0_all.deb
sudo apt-get update
sudo apt-get install esl-erlang
sudo apt-get install elixir
