create() creates duplicate Authors@R fields

[dtenenba]

> library(devtools)
> x <-  'person("Bioconductor Package", "Maintainer", email = "maintainer@bioconductor.org", role=c("aut", "cre"))'
> desc <- list()
> desc[["Authors@R"]] <- x
> create("foo", desc)
Creating package foo in .
No DESCRIPTION found. Creating default:

Package: foo
Title: 
Description: 
Version: 0.1
Authors@R: # getOptions('devtools.desc.author')
Depends: R (>= 3.0.1)
License: # getOptions('devtools.desc.license')
LazyData: true
Authors@R: person("Bioconductor Package", "Maintainer", email = "maintainer@bioconductor.org", role=c("aut", "cre"))

Note that Authors@R appears twice, and the resulting package can't be built by R CMD build. This is with devtools_1.3.99.

On another topic, I think it's misleading that it says "No DESCRIPTION found. Creating default". In fact we are passing a description parameter, and it does not contain all default values.