oauth2 package - pass in scope delimiter character, default to 'a single space

[DartBot]

This issue was originally filed by [email protected]

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when passing in a list of scopes to get access to for a user the code currently has a hard coded scope delimiter:

      if (!scopes.isEmpty) fields["scope"] = scopes.join(' ');

would it be possible to pass in a delimiter character, as I understand it facebook uses a comma rather than a space, so I don't think it is possible to use the oauth2 package to connect with facebook for this reason.

[sgjesse]

Added Area-Pkg, Pkg-oauth2, Triaged labels.

[DartBot]

This issue has been moved to dart-lang/tools#308.