prettytable-rs: even prettier → encoding error

I have rewritten the original issue

Hey there, I would love to draw line separators with these symbols:

.separators( &[format::LinePosition::Top],    format::LineSeparator::new('─', '┬', '┌', '┐'))
.separators( &[format::LinePosition::Intern], format::LineSeparator::new('─', '┼', '├', '┤'))
.separators( &[format::LinePosition::Bottom], format::LineSeparator::new('─', '┴', '└', '┘'))

however, there seems to be some sort of encoding problem, because they are not printed this way on the terminal

Expectation:

┌─────────────┬────────────┐
│ Title 1     | Title 2    │ 
├─────────────┼────────────┤
│ Value 1     | Value 2    │ 
├─────────────┼────────────┤
│ Value three | Value four │ 
└─────────────┴────────────┘

Result:

,
 Title 1      Title 2    
<$
 Value 1      Value 2    
<$
 Value three  Value four 
4▒

Do you have an idea what goes wrong here? Thanks