AuthCodeURL generates incomplete scopes

[jimzhan]

oauth2.go, line 117, the scopes simply joined by spaces, instead of commas Github.

"scope":         internal.CondVal(strings.Join(c.Scopes, " ")),

[adg]

GitHub is wrong. Quoth the spec:

The value of the scope parameter is expressed as a list of space-
delimited, case-sensitive strings.

https://tools.ietf.org/html/rfc6749#section-3.3

When authenticating with GitHub, provide your scopes as a single comma-separated value.