Build and test Erlang exercises with Rebar3

[lpil]

Now that Rebar 3 is the official build tool of Erlang should we use it here?

It would be a little friendlier as the command would be

rebar3 eunit

instead of

erl -make
erl -noshell -eval "eunit:test(accumulate, [verbose])" -s init stop

This would require changing the exercises to use the Erlang OTP project directory structure, which I think would be a good thing.

[kytrinyx]

@tmcgilchrist @lehoff @NobbZ any thoughts on rebar 3 (and Erlang OTP project directory structure)?

[NobbZ]

I think, migrating to rebar were a good thing as it would make most things much easier. But it would require the student to install just another tool (that he might want to use anyway) since rebar3 might be the officially supposed build tool, but it is not bundled with current versions of the erlang compiler and run time, this is true for debian based distributions at least.

Also I think this should be a migration that happens all at once, and not step by step. I can remember the confusion over at the haskell-track when they switched from runhaskell to stack, and the build tool used was different in every other exercise.

Also I do think, that the track should be revised in general, and I am unsure if we should do this revision in a single step while migrating to rebar or independent from that. I do tend towards doing it in seperate steps though.

[kytrinyx]

I do tend towards doing it in seperate steps though.

Likewise. I think that it would be easier to make one transition at a time.