Log Message:
textproc/hs-text-rope: update to text-rope-0.3

# 0.3

* Move `Data.Text.Utf16.Rope.Mixed` module to `Data.Text.Mixed.Rope`. \ 
`Data.Text.Utf16.Rope.Mixed` re-exports `Data.Text.Mixed.Rope` for legacy \ 
clients.
* Add `Data.Text.Utf8.Lines` and `Data.Text.Utf8.Rope` modules for ropes indexed \ 
by UTF-8 code units.
* Add UTF-8 indexing functionality to `Data.Text.Mixed.Rope`.
* The metrics stored internally in the rope nodes has changed, which should \ 
improve performance by making some re-measuring redundant. As a consequence, the \ 
time complexity of `Data.Text.Rope.lengthAsPosition` is now linear in the length \ 
of the last line.
* Add `getLine` functions to extract lines by 0-based index.