Add "new_name" parameter to repo transfer request (#2787)

[kgalli]

Resolves: #2787

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[gmlewis]

Thank you, @kgalli !
After you make the requested change, please run "go generate ./..." and push (not force-push) the results to this PR, as described in CONTRIBUTING.md.

[codecov]

Codecov Report

Merging #2788 (fce6b4a) into master (f96b64e) will not change coverage.
The diff coverage is n/a.

@@ Coverage Diff @@## master #2788 +/- ##
=======================================
Coverage 98.06% 98.06% =======================================
Files 132 132 Lines 11650 11650 =======================================
Hits 11424 11424 Misses 154 154 Partials 72 72 

Impacted Files	Coverage Δ
github/orgs_audit_log.go	100.00% <ø> (ø)
github/repos.go	98.84% <ø> (ø)

[kgalli]

@gmlewis thanks for the hint. I updated the code and run the generate command. Have to admit I haven't thought about the accessors. Very nice that you have generators in place for that.

[gmlewis]

Thank you, @kgalli !
LGTM.
Merging after tests pass.