Fixes ADMB version number

[kellijohnson-NOAA]

Concisely (20 words or less) describe the issue

Updates the version number of ADMB to 13.0, using a hard-coded value.

Please Link issue(s)

Resolves #373

If not, please add documentation before submitting the Pull Request.

• I have documented any new code added (or no new code was added)

is there an input change for users to Stock Synthesis?

• Yes, there was an input change

If so, please provide an example of the new inputs needed.

[New example stock synthesis input goes here]

Check which is true. This PR requires:

• no further changes to r4ss
• no further changes to the manual
• no further changes to SSI (the SS3 GUI)
• no further changes to the stock synthesis change log (new features, bug reports)

Describe any changes in r4ss/SS3 manual/SSI that are needed (if not checked):

If changes are needed in the change log, please fill in the table here:

Action	Topics	Type
[fix, new, or revise]	[e.g., biology. Use issue label options.]	[input, output, and/or calc, or ALL]

Additional information (optional):

[Rick-Methot-NOAA]

good

[iantaylor-NOAA]

Oops, good catch. I should have done this with the other changes to move to ADMB 13.0. We can do it all again for ADMB 13.1 in the next release.