swagger/fix: []string are not enum by swagger definition

[sapk]

[]string are not enum by swagger definition this led the generation of a client to think that repo.code,repo.issues,repo.ext_issues,repo.wiki,repo.pulls,repo.releases,repo.ext_wiki is an array of []string ([][]string).
By definition, enum are one of an array like Permission that can take one value from none,read,write,admin,owner.
This PR change the definition to an example to be able to generate a valid client from the swagger specs. Currently the generated client doesn't compile because it try convert the []string enum to [][]string

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[sapk]

Somewhat related (at least for the generate limitation part) : go-swagger/go-swagger#1942

[guillep2k]

Is it OK that units and permission have different representations?

[sapk]

Yes because permission only take one of the value (enum type) and units is a list (array) of manyof the value wich is not really an enum.

[sapk]

This could maybe improved by defining an Go enum type for units and declare that units is an array of this Type. I have try but I doesn't have anythings fully working and it need a lot of refactor to be done on other parts of code. There also seems to be issue whit that on go-swagger so I used the example fields.