Add support for Swift.

[sourcebits-rafeeq]

When can we expect support for Swift language?

[adam-waldenberg]

Hello. Somebody that knows the language well needs to add the support. Pull requests for new languages are always welcome. To read up on how language support in gitinspector works, see issue #59.

[adam-waldenberg]

Swift support added with #156, this will be merged into 0.5.0