Install Elixir dependencies before Node dependencies
Install Elixir dependencies before Node dependencies

Trying to install the node dependencies fails with the following error
if the Elixir dependencies are not installed first.
```
npm ERR! addLocal Could not install battle_snake/deps/phoenix
npm ERR! addLocal Could not install battle_snake/deps/phoenix_html
```

Dkendal/battle_snake,Dkendal/battle_snake,Dkendal/battle_snake,Dkendal/battle_snake,Dkendal/battle_snake