centos 7 is ambiguous in streams

[Curtis Hovey]

I was surprised to see centos 7 identified solely by "7" for the os/series:

        "com.ubuntu.juju:7:amd64": {
            "version": "1.24-beta5",
            "arch": "amd64",
            "versions": {
                "20150526": {
                    "items": {
                        "1.24-beta5-centos7-amd64": {
                            "release": "centos7",
                            "version": "1.24-beta5",
                            "arch": "amd64",
                            "size": 16208906,
                            "path": "devel/juju-1.24-beta5-centos7-amd64.tgz",
                            "ftype": "tar.gz",
                            "sha256": "0d9a8600c694aa1d57d2234287647f19a238c4e7f25ed596b84c42009ea8be8c"
                        }
                    }
                }
            }
        },

I can see this is intentional in the code, but I think a single digit will cause problems if we ever need to support another os that also uses simple digits. I prefer to see "centos7" as the series. As we have only a few days to change our minds, I am raising this bug. Wont Fix is a valid way to close this issue if we are certain "7" is the right choice for the next 5 to 10 years.

[Gabriel Samfira (gabriel-samfira)]

The following review requests fix this bug:

http://reviews.vapour.ws/r/2062/
http://reviews.vapour.ws/r/2063/