bwrap 1.3.0

RELEASE: 1.3.0, 6eaa3ca

BACKWARD_COMPATIBLE_CHANGES:

• Introduce wrap_nobrk macro.
• Change rust-version from default to 1.47.
• Change rust edition from 2021 to 2018.
• Add doctest examples, disable doctest.

BACKWARD_COMPATIBLE_FIXES:

• Handle append/prepend in wrap_maybrk macro.
• Fix incorrect width limit for Japanese example, by @kyoheiu.
• Add dependencies' licenses.