Added option for NULL for languages to see all

[muschellij2]

Please ensure the following before submitting a PR:

• [X] if suggesting code changes or improvements, open an issue first
• [X] for all but trivial changes (e.g., typo fixes), add your name to DESCRIPTION
• [X] for all but trivial changes (e.g., typo fixes), documentation your change in NEWS.md with a parenthetical reference to the issue number being addressed
• [X] if changing documentation, edit files in /R not /man and run devtools::document() to update documentation
• [X] make sure R CMD check runs without error before submitting the PR

This fixes #5 for listing all voices.

[muschellij2]

Does this seem to work on your end?

[muschellij2]

So I think this works but I'm not sure @cloudyr or @leeper is still maintaining...

[muschellij2]

This should now work. Good to see @antoine-sachet maintaining!

[codecov-io]

Codecov Report

Merging #6 into master will not change coverage. The diff coverage is 0%.

@@         Coverage Diff         @@
##           master   #6   +/-   ##
===================================
  Coverage       0%   0%           
===================================
  Files           4    4           
  Lines          87   89    +2     
===================================
- Misses         87   89    +2

Impacted Files	Coverage Δ
R/list_voices.R	0% <0%> (ø)	:arrow_up:
R/synthesize.R	0% <0%> (ø)	:arrow_up:

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update c11b9c9...bc37302. Read the comment docs.

[antoine-sachet]

Thanks! Looks good to me, I'll start merging. In the future, please avoid committing your Rproj file. It contains your local project options which, if committed, overwrite the project options of other contributors.

Close #5.

[antoine-sachet]

Merged manually. Close #5.

Thanks again for your contribution!