tsibble 0.8.2

This is a patch release.

• Fixed bugs for losing the "ordered" attribute when renaming a tsibble, introduced in v0.8.1 (#126).
• Fixed bug in as.ts.tbl_ts() for handling a tsibble of one row (#124).
• Fixed issue of nest.tbl_ts() for naming (#123).
• Fixed floating issues for duplicated indices in as_tsibble.ts() (#128).