Major Performance Enhancement
 - `use`/`nvm_die_on_prefix`: replicate npm config algorithm and remove `npm config` call (#2317)

Fixes
 - `nvm ls-remote`: accept versions that end with a dot (#2310)
 - `nvm_ls`: zsh: unset `markdirs` and `local_options` (#2316)
 - `nvm_die_on_prefix`: use directory comparison rather than string (#2316)

Docs
 - improve `nvm --help` output (#2301)
 - [readme] bash shell integration: amend example (#2313)

Tests
 - Fix `nvm_ls_current` fast test (#2322)
 - Fix nvm unload fast test cleanup (#2332)
 - Drop deprecated `sudo:` option in TravisCI config (#2307)