Support for where/in queries

[curi1119]

This PR fixies where in query.

If use where in in Ecto like follow,

Model.Employee
  |> where([x], x.employee_id in ^[3, 5, 7])
  |> Repo.all()

Etso build ETS qeury like this.

{{:"$1", :"$2", :"$3", :"$4", :"$5", :"$6", :"$7", :"$8", :"$9", :"$10", :"$11"},
 [{:orelse, {:==, :"$1", nil}, {:==, :"$1", 3}}],
 [
   [:"$1", :"$2", :"$3", :"$4", :"$5", :"$6", :"$7", :"$8", :"$9", :"$10",
    :"$11"]
 ]}

This :orelse query is not expected.

Expected :orelse:

{{:"$1", :"$2", :"$3", :"$4", :"$5", :"$6", :"$7", :"$8", :"$9", :"$10", :"$11"},
 [{:orelse, {:==, :"$1", 7}, {:orelse, {:==, :"$1", 5}, {:==, :"$1", 3}}}],
 [
   [:"$1", :"$2", :"$3", :"$4", :"$5", :"$6", :"$7", :"$8", :"$9", :"$10",
    :"$11"]
 ]}

[evadne]

This is very good. Thank you.

[evadne]

Merged & Released in Etso 0.1.2.

Thank you for your contribution.