Support OCaml style floating point syntax without trailing numbers after dot

[Michał Łępicki]

Currently this Caramel code compiles:

let main _ =
  42.

to this Erlang:

% Source code generated with Caramel.
-module(main).

-export([main/1]).

-spec main(_) -> float().
main(_) -> 42..

Erlang compilation fails with:

main.erl:6: syntax error before: '..'

This should either:
a) compile to 42.0 in Erlang
b) or print a helpful error when compiling Caramel

Caramel 0.1, Erlang 23.2.2