v0.1.6

• Support mouse scroll. (#2)
  • Handle mouse events for both crossterm and termion backends.
  • TextArea::scroll method was added.
  • Key::MouseScrollUp and Key::MouseScrollDown virtual keys are added to Key enum so that custom backends can support mouse scrolling.
  • CursorMove::InViewport variant was added to CursorMove enum, which ensures the cursor to be within the viewport.
• Add TextArea::alignment and TextArea::set_alignment to set the text alignment of textarea. Note that right and center alignments don't work well with line number so calling TextArea::set_alignment with them automatically disables it. (#3, thanks @Volkalex28)
  
• Set rust-version to 1.56.1 in Cargo.toml to show MSRV explicitly.