Update deprecated syntax for future rstan compatibility

[andrjohns]

Now that rstan 2.26 is available on CRAN we need to update the deprecated syntax in your package's Stan models, otherwise it will fail to install with an upcoming version of RStan.

The following updates have been made:

• New array syntax

More information about the deprecated and removed syntax in Stan can be found here:

• https://mc-stan.org/docs/functions-reference/deprecated-functions.html
• https://mc-stan.org/docs/functions-reference/removed-functions.html

If you could merge and submit to CRAN soon, it would be greatly appreciated.

Let me know if you have any questions about these changes.

Thanks!

[helske]

Thanks Andrew! Will submit to CRAN immediately.

[helske]

As expected, this works. @andrjohns would you like me to add you as a contributor in the DESCRIPTION, given that you have done several PRs for walker?

[andrjohns]

As expected, this works. @andrjohns would you like me to add you as a contributor in the DESCRIPTION, given that you have done several PRs for walker?

Great! No need to add me as a contributor, since my PRs have just been boilerplate and pretty automated

[helske]

This is now on CRAN.

[andrjohns]

Brilliant, thanks!