Running alchemist commands against an existing erlang node

[jtmoulia]

I sometimes want to run alchemist commands against an existing erlang node rather than boot up a new node. This would potentially help with issues like #50, #46, #33, etc.

I knocked together an example of what this might look like for autocomplete using distel over here. This could be expanded to back thing like alchemist's help/whatever functionality.

I like how alchemist currently does things, and distel would be an added dependency, so I think this might work well as an optional feature.

[jtmoulia]

❤️ #131