How to perform unit testing in binary cargo package with this structure below
|-- Cargo.lock
|-- Cargo.toml
|-- src
| |-- bin
| | |-- clean.rs
| | |-- csv2json.rs
| | |-- csvsql.rs
| | |-- cut.rs
| | |-- format.rs
| | |-- grep.rs
| | |-- in2csv.rs
| | |-- join.rs
| | |-- look.rs
| | |-- sort.rs
| | |-- sql2csv.rs
| | |-- stack.rs
| | |-- stat.rs
| |-- common
| | |-- help_descriptions.rs
| | |-- input.rs
| | |-- input_2.rs
| | |-- input_3.rs
| | |-- lib.rs
| | |-- number_decriptive.rs
| | |-- number_decriptives.rs
| | |-- number_description.rs
| | |-- number_descriptions.rs
| | |-- number_descriptive.rs
| | |-- number_descriptives.rs
| | |-- sql_functions.rs
| | |-- text_descriptives.rs
| |-- data.csv
| -- target
|-- debug
|-- 2018.xlsx
|-- 2019.xlsx